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 A205004 #5 Mar 30 2012 18:58:09 %S A205004 3,3,6,10,6,15,10,36,10,21,21,15,28,15,21,136,45,21,55,21,36,28,78,45, %T A205004 28,36,28,66,120,36,136,528,36,55,36,78,190,66,45,55,231,45,253,45,55, %U A205004 91,300,153,55,78,66,55,378,55,91,66,78,136,465,66 %N A205004 Least k(k+1)/2 such that n divides k(k+1)/2-j(j+1)/2 for some j<k. %C A205004 For a guide to related sequences, see A204892. %t A205004 (See the program at A205002.) %Y A205004 Cf. A204892, A205002. %K A205004 nonn %O A205004 1,1 %A A205004 _Clark Kimberling_, Jan 21 2012