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 A047109 #8 Jan 12 2025 21:01:38 %S A047109 1,1,5,31,151,917,5619,33627,210911,1326395,8366161,53441835, %T A047109 342477957,2203613164,14248253995,92379163952,600644552471, %U A047109 3915699367751,25579440322831,167423682425912,1097738520430457,7208383257398805 %N A047109 T(2n,n), array T as in A047100. %K A047109 nonn %O A047109 0,3 %A A047109 _Clark Kimberling_. Definition revised Dec 08 2006 %E A047109 Name corrected by _Sean A. Irvine_, Jan 12 2025