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 A049707 #8 Aug 07 2021 01:11:33 %S A049707 1,1,3,6,9,12,17,22,27,33,39,48,56,64,71,82,92,105,116,129,139,153, %T A049707 167,183,197,213,227,247,262,285,303,325,342,362,379,403,426,451,471, %U A049707 497,520,551,576,605,627,657,685,720,746,778,802,839,870,907,934,967 %N A049707 a(n) = T(n,n+3), array T as in A049704. %K A049707 nonn %O A049707 0,3 %A A049707 _Clark Kimberling_ %E A049707 More terms from _Sean A. Irvine_, Aug 06 2021