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 A027213 #13 Oct 25 2019 16:52:59 %S A027213 1,2,6,27,92,440,1556,7514,27082,130883,477258,2303413,8465592, %T A027213 40783083,150735628,724837891,2690363900,12915186640,48093650016, %U A027213 230526280814,860654319126,4119854160332,15413262342946,73695109608352,276180051478904,1319136935150530,4950605267226796 %N A027213 Sum of squares of numbers in row n of array T given by A026725. %p A027213 A027213 := proc(n) %p A027213 add( A026725(n,k)^2,k=0..n) ; %p A027213 end proc: # _R. J. Mathar_, Oct 21 2019 %K A027213 nonn %O A027213 0,2 %A A027213 _Clark Kimberling_ %E A027213 More terms from _Sean A. Irvine_, Oct 24 2019