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 A205007 #11 Sep 29 2018 18:41:34 %S A205007 2,1,1,1,1,2,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1, %T A205007 1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,1,1, %U A205007 1,1,1,1,1,1,1,1,1,2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1 %N A205007 a(n) = (1/n)*A205006(n), where A205006(n) = s(k)-s(j), with (s(k),s(j)) the least pair of distinct triangular numbers for which n divides their difference. %C A205007 For a guide to related sequences, see A204892. %H A205007 Antti Karttunen, <a href="/A205007/b205007.txt">Table of n, a(n) for n = 1..23515</a> %t A205007 (See the program at A205002.) %o A205007 (PARI) A205007(n) = for(k=2,oo,my(sk=binomial(k+1,2)); for(j=1,k-1,if(!((sk-binomial(j+1,2))%n),return((sk-binomial(j+1,2))/n)))); \\ _Antti Karttunen_, Sep 27 2018 %Y A205007 Cf. A000217, A205002, A205006, A204892. %Y A205007 Cf. A318894 (gives the positions terms larger than one). %K A205007 nonn %O A205007 1,1 %A A205007 _Clark Kimberling_, Jan 21 2012 %E A205007 More terms from _Antti Karttunen_, Sep 27 2018