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 A047768 #9 Mar 07 2020 01:22:31 %S A047768 0,0,1,5,26,133,708,3861,21604,123266,715221,4206956,25032840, %T A047768 150413348,911379384,5562367173,34164355848,211015212580, %U A047768 1309815397995,8166460799805,51120054233490,321156223592865,2024257417812240,12797201858645100 %N A047768 a(n) = A047766(6n+2). %C A047768 Is this the same as A047755? - _R. J. Mathar_, Oct 18 2008 %K A047768 nonn %O A047768 0,4 %A A047768 _N. J. A. Sloane_