This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A334001 #15 Oct 05 2020 01:02:06 %S A334001 2,2,4,4,6,8,8,10,10,12,16,12,16,14,18,12,22,24,20,16,22,22,24,26,22, %T A334001 26,28,16,30,30,36,24,34,36,32,30,30,44,42,44,38,44,50,34,44,46,54,36, %U A334001 50,60,56,30,50,56,56,46,54,56,68,36,68,54,56,46,44,66,54 %N A334001 The number of odd values in the n-th column of A279212. %C A334001 All of the values in this sequence are even, as shown in Alec Jones's proof that each column of A279212 has a finite number of odd entries. %C A334001 Conjecture: a(n) <= 2*n. %H A334001 Peter Kagey, <a href="/A334001/b334001.txt">Table of n, a(n) for n = 1..1024</a> %H A334001 Alec Jones, <a href="/A279212/a279212.pdf">Proof that columns of A279212 have finitely many odd entries</a>. %H A334001 Peter Kagey, <a href="/A279212/a279212.png">Bitmap showing parity of first 1024 rows and 512 columns of A269212</a>. (Odd values are white; even values are black.) %e A334001 For n = 3, the third column of A279212 is 11, 39, 119, 330, 870, 2209, 5454, 13176, 31280, 73200, ... which contains a(3) = 4 odd values. %Y A334001 Cf. A279212. %K A334001 nonn %O A334001 1,1 %A A334001 _Peter Kagey_, Apr 12 2020