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 A047138 #8 Jan 20 2020 08:18:26 %S A047138 1,4,14,48,179,656,2394,8744,32791,123188,463211,1744076,6632688, %T A047138 25303978,96699766,370030836,1422210560,5479757300,21147107145, %U A047138 81707846148,316422360163,1227500661756,4768032430608,18539704936398 %N A047138 a(n) = T(n,n+3), array T as in A047130. %Y A047138 Cf. A047130. %K A047138 nonn %O A047138 0,2 %A A047138 _Clark Kimberling_ %E A047138 Definition corrected by _Georg Fischer_, Jan 20 2020