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 A049626 #7 Aug 05 2021 20:01:44 %S A049626 3,3,6,8,11,12,16,17,20,22,25,26,30,31,34,36,39,40,44,45,48,50,53,54, %T A049626 58,59,62,64,67,68,72,73,76,78,81,82,86,87,90,92,95,96,100,101,104, %U A049626 106,109,110,114,115,118,120,123,124,128,129,132,134,137,138,142 %N A049626 a(n) = T(n,4), array T as in A049615. %K A049626 nonn %O A049626 0,1 %A A049626 _Clark Kimberling_ %E A049626 More terms from _Sean A. Irvine_, Aug 05 2021