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 A171956 #3 Mar 30 2012 16:51:56 %S A171956 10,15,29,32,43,74,77,100,118,150,164,170,171,181,193,210,221,244,265, %T A171956 271,272,305,311,312,317,332,346,419,444,453,457,459,463,465,467,485, %U A171956 506,547,597,607,613,614,619,644,653,664,697,707,717,719 %N A171956 Positions of 6's in A181391. %H A171956 N. J. A. Sloane, <a href="/A171956/b171956.txt">Table of n, a(n) for n = 1..5453</a> %Y A171956 Cf. A181391, A171865, A171951-A171956. %K A171956 nonn %O A171956 1,1 %A A171956 _N. J. A. Sloane_, Oct 29 2010