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 A306525 #9 Feb 21 2019 20:43:43 %S A306525 0,1,3,12,53,282,1753,12566,102233,931746,9408941,104310042, %T A306525 1259745925,16464164978,231539899697,3486551697582,55972130401073, %U A306525 954322312212546,17222351842894933,327979242711784226,6573122342554664381,138292026914011788882 %N A306525 Row sums of A306234. %H A306525 Alois P. Heinz, <a href="/A306525/b306525.txt">Table of n, a(n) for n = 0..450</a> %p A306525 a:= proc(n) option remember; `if`(n<5, [0, 1, 3, 12, 53][n+1], %p A306525 (2*(2*n^2-9*n+6)*a(n-1) -(2*n^3-13*n^2+21*n-8)*a(n-2) %p A306525 -(4*n^2-21*n+30)*a(n-3) +(2*n^3-19*n^2+63*n-71)*a(n-4) %p A306525 -(2*n-5)*(n-4)*a(n-5)) / (2*n-7)) %p A306525 end: %p A306525 seq(a(n), n=0..23); %Y A306525 Row sums of A306234. %K A306525 nonn %O A306525 0,3 %A A306525 _Alois P. Heinz_, Feb 21 2019