News for hackers. Stuff that matters.
Re:The On-Line Encyclopedia of Integer Sequences by ludwigvan on Saturday October 26, 2019 @09:30PM (#21367377)
A fun question I have been pondering recently: what is the smallest positive integer that has not yet been written or uttered by a human being?
Re:The On-Line Encyclopedia of Integer Sequences by missblit on Sunday October 27, 2019 @12:51AM (#21367935)
You can try to get a rough idea by doing web searches for various random integers of different lengths (courtesy of random.org, which graced me with lots of 7's).

7 - A lucky number

92 - How old Lady Gaga wants to be when she retires

420 - A class of dinghy

7260 - A wireless card

5108 - A section in the U.S. Code about supplemental claims

51664 - A hydraulic filter

794101 - A postal code in India

7578146 - A patent number of a knitting loom clip

74703567 - A clothing trademark serial number for "authentic bad lands"

760314276 - No useful search results.

2641309883 - No useful search results

24235991397 - One (useless) search result

415865230233 - Zero search results

Re:The On-Line Encyclopedia of Integer Sequences by braythwayt on Saturday October 26, 2019 @09:51PM (#21367432)
Were Raymond Smullyan still with us, he would point out that you just answered your own question. And yet didn't. In which case you did. Provided you didn't.

Another example:

"The smallest integer that has a description too long to fit in a Hacker News comment."

Re:The On-Line Encyclopedia of Integer Sequences by ivalm on Saturday October 26, 2019 @10:28PM (#21367541)
But you can definitely say "what is the meta information or algorithm to compute X". E.g. Pi is an irrational number, but we have a bunch of ways to specify pi (we just can't explicitly write down the full sequence of numbers). Another interesting thing, while the full sequence is not computable, any particular precision IS computable (ie for any number Y that you can write down exactly, you can compute the Y'th digit of pi).
Re:The On-Line Encyclopedia of Integer Sequences by chongli on Sunday October 27, 2019 @10:15AM (#21369808)
These sorts of self-referential statements are actually forbidden in the axioms of Zermelo-Fraenkel set theory because they require unrestricted comprehension [1]. ZF set theory specifically restricted comprehension to avoid Russell’s paradox [2] as well as countless other statements, like these, which lead to absurdities in math.

Fun stuff anyway!

[1] https://en.wikipedia.org/wiki/Axiom_schema_of_specification#...

[2] https://en.wikipedia.org/wiki/Russell%27s_paradox

Re:The On-Line Encyclopedia of Integer Sequences by braythwayt on Sunday October 27, 2019 @02:20PM (#21371465)
Absolutely!

But it is more than fun to explore them, as Smullyan points out. For example, it leads to discussions like, “What is a description?” Which is near and dear to my heart, as it leads to “What is a program?” and, “What is the specification of the machine that runs the program?”

Re:The On-Line Encyclopedia of Integer Sequences by chongli on Sunday October 27, 2019 @03:18PM (#21371791)
Or some of my favourites:

“What is a number? Do numbers exist?”

I’ve been having a fantastic time in my philosophy of math course this term. It’s incredible how deep and how long these debates have been running. Cantor, Frege, Russell, Hilbert, Heyting, Gödel, Quine, and on and on!

Re:The On-Line Encyclopedia of Integer Sequences by braythwayt on Sunday October 27, 2019 @08:47PM (#21373468)
I forget which book is the source of this, but I recall Smullyan writing about (I hope I have it roughly right) asking a child whether they could prove something they knew about mathematics or logic, and the child replied "What is a proof?"

Smullyan said that this was--if you took it literally--an incredibly deep question.

Re:The On-Line Encyclopedia of Integer Sequences by zzo38computer on Saturday October 26, 2019 @10:05PM (#21367472)
What is the limit? This <textarea> element does not specify one, nor do I see any limit mentioned in the text of this web page.
Re:The On-Line Encyclopedia of Integer Sequences by saagarjha on Saturday October 26, 2019 @10:50PM (#21367613)
I want to post an extremely long comment and see what the limit is now…
Re:The On-Line Encyclopedia of Integer Sequences by feikname on Sunday October 27, 2019 @12:42AM (#21367914)
It seems to be 10k chars.

Otherwise, it displays a "message too long" error.

Re:The On-Line Encyclopedia of Integer Sequences by braythwayt on Sunday October 27, 2019 @09:49AM (#21369660)
10k characters might be a browser limit, but I tried pasting 9,000 characters from one of my essays into a comment, and it was also rejected as being too long.
Re:The On-Line Encyclopedia of Integer Sequences by booleandilemma on Saturday October 26, 2019 @09:52PM (#21367434)
Re:The On-Line Encyclopedia of Integer Sequences by Someone on Sunday October 27, 2019 @07:05AM (#21369001)
If you limit it to mathematicians, it was, at some time, 8795 ;-) (https://oeis.org/wiki/Frequency_of_appearance_in_the_OEIS_da...)

More interestingly, the set of integers seems to be split into two sets: those that occur relatively often, and those that occur relatively rarely (same page)

Re:The On-Line Encyclopedia of Integer Sequences by nabla9 on Sunday October 27, 2019 @03:30AM (#21368331)
Every time you answer the question the correct answer changes.
Re:The On-Line Encyclopedia of Integer Sequences by rsrsrs86 on Sunday October 27, 2019 @07:09PM (#21373069)
Side effects in math!!!!!!!!!!