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 A081126 #34 Sep 25 2021 13:11:12 %S A081126 1,2,5,16,53,206,817,3620,16361,80218,401501,2139512,11641885, %T A081126 66599846,388962953,2367284236,14700573137,94523836850,619674301621, %U A081126 4186249123808,28809504493061,203556335785342,1463877667140065 %N A081126 Duplicate of A018191. %K A081126 dead %O A081126 0,2