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 A278539 #6 Nov 24 2016 09:29:39 %S A278539 1,2,1,3,2,4,1,5,2,6,3,7,1,8,2,9,4,10,1,11,3,12,5,13,2,14,1,15,6,16,2, %T A278539 17,4,18,7,19,3,20,1,21,8,22,2,23,5,24,9,25,1,26,3,27,10,28,4,29,6,30, %U A278539 11,31,2,32,1,33,12,34,2,35,7,36,13,37,3,38,5,39,14,40,1,41,8,42,15,43,4,44,2,45,16,46,1,47,9,48,17,49,6,50,3,51,18,52,2,53 %N A278539 a(n) = index of the column where n is located in array A278505. %C A278539 Ordinal transform of A278538 (as the rows of A278505 are strictly growing). %H A278539 Antti Karttunen, <a href="/A278539/b278539.txt">Table of n, a(n) for n = 1..10707</a> %F A278539 a(n) = 1 + A278529(n). %o A278539 (Scheme) (define (A278539 n) (+ 1 (A278529 n))) %Y A278539 One more than A278529. %Y A278539 Cf. A278505, A278538, A278537. %K A278539 nonn %O A278539 1,2 %A A278539 _Antti Karttunen_, Nov 23 2016