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 A278508 #6 Nov 24 2016 09:28:50 %S A278508 2,5,4,9,11,6,15,21,17,8,25,37,33,23,10,31,51,55,45,29,12,43,73,85,75, %T A278508 57,35,14,61,99,121,111,97,69,41,16,67,127,151,159,145,115,81,47,18, %U A278508 87,163,193,211,199,171,135,93,53,20,103,187,247,271,267,243,205,157,105,59,22,123,229,303,339,343,319,283,231,175,117,65,24 %N A278508 Transpose of square array A278507. %C A278508 See A278507. %H A278508 Antti Karttunen, <a href="/A278508/b278508.txt">Table of n, a(n) for n = 1..7260; the first 120 antidiagonals of the array</a> %o A278508 (Scheme) (define (A278507 n) (A278507bi (A002260 n) (A004736 n))) ;; Code for A278507bi given in A278507. %Y A278508 Transpose: A278507. %K A278508 nonn,tabl %O A278508 1,1 %A A278508 _Antti Karttunen_, Nov 23 2016