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 A205028 #9 Mar 30 2012 18:58:10 %S A205028 1,1,2,1,1,2,2,3,1,1,4,2,5,2,3,7,7,1,8,1,5,4,10,2,2,5,1,1,13,3,14,15, %T A205028 2,7,1,2,17,8,3,1,19,5,20,3,4,10,22,6,3,2,5,4,25,1,8,4,6,13,28,3 %N A205028 The index j<k such that n divides s(k)-s(j), where k is the least index (A205018) for which such j exists, and s(k)=k*(k+1). %C A205028 For a guide to related sequences, see A204892. %t A205028 (See the program at A205018.) %Y A205028 Cf. A205018, A204892. %K A205028 nonn %O A205028 1,3 %A A205028 _Clark Kimberling_, Jan 22 2012