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Do you have a mathematically attractive face?

https://www.doimog.com
1•a_n•30s ago•1 comments

Code only says what it does

https://brooker.co.za/blog/2020/06/23/code.html
1•logicprog•5m ago•0 comments

The success of 'natural language programming'

https://brooker.co.za/blog/2025/12/16/natural-language.html
1•logicprog•6m ago•0 comments

The Scriptovision Super Micro Script video titler is almost a home computer

http://oldvcr.blogspot.com/2026/02/the-scriptovision-super-micro-script.html
2•todsacerdoti•6m ago•0 comments

Discovering the "original" iPhone from 1995 [video]

https://www.youtube.com/watch?v=7cip9w-UxIc
1•fortran77•7m ago•0 comments

Psychometric Comparability of LLM-Based Digital Twins

https://arxiv.org/abs/2601.14264
1•PaulHoule•9m ago•0 comments

SidePop – track revenue, costs, and overall business health in one place

https://www.sidepop.io
1•ecaglar•11m ago•1 comments

The Other Markov's Inequality

https://www.ethanepperly.com/index.php/2026/01/16/the-other-markovs-inequality/
1•tzury•13m ago•0 comments

The Cascading Effects of Repackaged APIs [pdf]

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=6055034
1•Tejas_dmg•15m ago•0 comments

Lightweight and extensible compatibility layer between dataframe libraries

https://narwhals-dev.github.io/narwhals/
1•kermatt•18m ago•0 comments

Haskell for all: Beyond agentic coding

https://haskellforall.com/2026/02/beyond-agentic-coding
2•RebelPotato•21m ago•0 comments

Dorsey's Block cutting up to 10% of staff

https://www.reuters.com/business/dorseys-block-cutting-up-10-staff-bloomberg-news-reports-2026-02...
2•dev_tty01•24m ago•0 comments

Show HN: Freenet Lives – Real-Time Decentralized Apps at Scale [video]

https://www.youtube.com/watch?v=3SxNBz1VTE0
1•sanity•25m ago•1 comments

In the AI age, 'slow and steady' doesn't win

https://www.semafor.com/article/01/30/2026/in-the-ai-age-slow-and-steady-is-on-the-outs
1•mooreds•33m ago•1 comments

Administration won't let student deported to Honduras return

https://www.reuters.com/world/us/trump-administration-wont-let-student-deported-honduras-return-2...
1•petethomas•33m ago•0 comments

How were the NIST ECDSA curve parameters generated? (2023)

https://saweis.net/posts/nist-curve-seed-origins.html
2•mooreds•34m ago•0 comments

AI, networks and Mechanical Turks (2025)

https://www.ben-evans.com/benedictevans/2025/11/23/ai-networks-and-mechanical-turks
1•mooreds•34m ago•0 comments

Goto Considered Awesome [video]

https://www.youtube.com/watch?v=1UKVEUGEk6Y
1•linkdd•36m ago•0 comments

Show HN: I Built a Free AI LinkedIn Carousel Generator

https://carousel-ai.intellisell.ai/
1•troyethaniel•38m ago•0 comments

Implementing Auto Tiling with Just 5 Tiles

https://www.kyledunbar.dev/2026/02/05/Implementing-auto-tiling-with-just-5-tiles.html
1•todsacerdoti•39m ago•0 comments

Open Challange (Get all Universities involved

https://x.com/i/grok/share/3513b9001b8445e49e4795c93bcb1855
1•rwilliamspbgops•40m ago•0 comments

Apple Tried to Tamper Proof AirTag 2 Speakers – I Broke It [video]

https://www.youtube.com/watch?v=QLK6ixQpQsQ
2•gnabgib•42m ago•0 comments

Show HN: Isolating AI-generated code from human code | Vibe as a Code

https://www.npmjs.com/package/@gace/vaac
1•bstrama•43m ago•0 comments

Show HN: More beautiful and usable Hacker News

https://twitter.com/shivamhwp/status/2020125417995436090
3•shivamhwp•43m ago•0 comments

Toledo Derailment Rescue [video]

https://www.youtube.com/watch?v=wPHh5yHxkfU
1•samsolomon•45m ago•0 comments

War Department Cuts Ties with Harvard University

https://www.war.gov/News/News-Stories/Article/Article/4399812/war-department-cuts-ties-with-harva...
9•geox•49m ago•1 comments

Show HN: LocalGPT – A local-first AI assistant in Rust with persistent memory

https://github.com/localgpt-app/localgpt
3•yi_wang•50m ago•0 comments

A Bid-Based NFT Advertising Grid

https://bidsabillion.com/
1•chainbuilder•53m ago•1 comments

AI readability score for your documentation

https://docsalot.dev/tools/docsagent-score
1•fazkan•1h ago•0 comments

NASA Study: Non-Biologic Processes Don't Explain Mars Organics

https://science.nasa.gov/blogs/science-news/2026/02/06/nasa-study-non-biologic-processes-dont-ful...
3•bediger4000•1h ago•2 comments
Open in hackernews

Sequence and first differences together list all positive numbers exactly once

https://oeis.org/A005228
81•andersource•7mo ago

Comments

8organicbits•7mo ago
OEIS is such a wonderful reference. I've had occasions where software I was building needed to compute certain sequences, but I hadn't yet figured out the underlying math. I popped the sequence into OEIS and found the closed form solution. It was a huge productivity boost.
nurettin•7mo ago
For me it was a favorite place to visit every so often. I also really enjoyed mathworld.wolfram.com a few decades ago. (A true shame that he went insane)
volemo•7mo ago
> A true shame that he went insane

Could you elaborate on your reasons for calling Eric Weisstein insane?

Rexxar•7mo ago
He probably intends to call Stephen Wolfram like that. But it's ridiculous to call him insane because he seems a little obsessed by cellular automatons.
nurettin•7mo ago
Weisstein is amazing. Wolfram has the "unified theory of everything" disease. So much so that he sponsored dozens of youtube channels to talk about it.
foodevl•7mo ago
I don't know (and don't need you to elaborate on) exactly what you're referring to in that last sentence, but I suspect you are confusing Eric W. Weisstein with Eric Weisstein.
quietbritishjim•7mo ago
More likely he's confusing the mathworld author with Stephen Wolfram
lutusp•7mo ago
> A true shame that he went insane

I assume you're referring to Stephen Wolfram, not Neil Sloane, but it seems many people would like clarification.

As to Wolfram, assuming this is your focus, nothing undermines one's sanity as reliably as complete success. Not to accept your premise, only to explain it.

HocusLocus•7mo ago
Like 'even and odd' on steroids.
kleiba•7mo ago
Coding exercise: write a function

    boolean isInSequence(n):
that decides whether the given integer is part of that sequence or not. However, pre-storing the sequence and only performing a lookup is not allowed.
rokob•7mo ago
return n >= 0
r0uv3n•7mo ago
2 for example is not in the sequence. Remember that you need the first differences to this sequence to obtain all natural numbers
rokob•7mo ago
Hah oh right duh
vbezhenar•7mo ago
Compute the sequence until you get n or m > n?
haskellshill•7mo ago
How about the following Haskell program?

    rec ((x:xs),p) = (filter (/= p+x) xs,p+x)
    sequ = map snd $ iterate rec ([2..],1)
sequ is an infinite list of terms of the sequence A005228.
sltkr•7mo ago
That just enumerates the entire sequence; I think the challenge is to do it faster than that.

By the way, the use of `filter` makes your implementation unnecessarily slow. (The posted link also contains Haskell code, which uses `delete` from Data.List instead of `filter`, which is only slightly better.)

I'd solve it like this, which generates both sequences in O(n) time, and the mutual recursion is cute:

    a005228 = 1 : zipWith (+) a005228 a030124

    a030124 = go 1 a005228 where
        go x ys
            | x < head ys = x     : go (x + 1) ys
            | otherwise   = x + 1 : go (x + 2) (tail ys)
asboans•7mo ago
I don’t know but I think I could probably implement IsInSequenceOrFirstDifferences(n)
cluckindan•7mo ago
Recursive (n choose 2) is my favorite.

https://oeis.org/A086714

If you think about it, it quantifies emergence of harmonic interference in the superposition of 4 distinct waveforms. If those waveforms happen to have irrational wavelengths (wrt. each other), their combination will never be in the same state twice.

This obviously has implications for pseudorandomness, etc.

OscarCunningham•7mo ago
Is there a sequence where the sequence and all its differences contain each positive integer once?

Something like

    1 3 9   26  66
     2 6  17  40
      4 11  23
       7  12
        5
Oh, here it is: https://oeis.org/A035313
thaumasiotes•7mo ago
> Oh, here it is: https://oeis.org/A035313

That sequence is not known to match what you asked for:

>> Conjecturally, every positive integer occurs in the sequence or one of its n-th differences, which would imply that the sequence and its n-th differences partition the positive integers.

For an intuition of why this might be hard to prove, note that you had to insert 7 into your structure before you inserted 5. In the general case, there might be a long waiting period before you're able to place some particular integer n. It might be infinitely long.

vishnugupta•7mo ago
Can someone please explain this to me? I tried to make sense but couldn’t.
Horffupolde•7mo ago
The sequence union the differences span all integer values.
munchler•7mo ago
The initial sequence is 1, 3, 7, 12, 18, 26, 35, etc. The difference between each term in that sequence produces a second sequence: 2, 4, 5, 6, 8, 9, 10, etc. If you merge those two sequences together in sorted order, you get 1, 2, 3, 4, 5, 6, 7, etc. Each whole number appears in the result exactly once.
vishnugupta•7mo ago
Really good explainer. Thank you!
card_zero•7mo ago
By end of the sequence shown on the page, the contiguous part has only reached 61. After that it's full of gaps: it's hit 1689, but has not yet hit 62. The last three differences shown there are 59, 60, 61. So it will list all integers mainly because the differences are increasing similar to the ordinary number line.
Aardwolf•7mo ago
I wonder why the title of the sequence isn't set to "Hofstadter's sequence" since that seems to be what it's called according to A030124 when it refers back to this one
andersource•7mo ago
Hofstadter introduces several sequences in GEB, [0] may be an interesting submission on its own but I was especially captivated by this self-referencing one. Plus a title including both Hofstadter's sequence and a description is too long for HN and I preferred the descriptive one

[0] https://en.wikipedia.org/wiki/Hofstadter_sequence

Aardwolf•7mo ago
I meant the title as it appears in OEIS, not as it appears on HN :)
andersource•7mo ago
Ah :)

From my (limited) experience the OEIS titles lean strongly to the descriptive side too. But maybe also to avoid ambiguity regarding to which one is it from his sequences?