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 A110125 #11 Jun 17 2019 15:21:15
%S A110125 1,1,1,9,43,213,1507,12537,114325,1144221,12512373,148351881,
%T A110125 1892798733,25816700309,374406371121,5748436717505,93098093268755,
%U A110125 1585364420710205,28305454044441843,528500175862180033,10295596472841577779
%N A110125 Row sums of a scaled Legendre triangle.
%C A110125 Row sums of A110124.
%H A110125 Robert Israel, <a href="/A110125/b110125.txt">Table of n, a(n) for n = 0..478</a>
%F A110125 a(n)=sum{k=0..n, 2^(n-k)*LegendreP(n-k, k)}.
%p A110125 f := n -> add(2^(n-k)*orthopoly[P](n-k,k),k=0..n):
%p A110125 map(f, [$0..30]); # _Robert Israel_, Jun 17 2019
%o A110125 (PARI) a(n)=sum(k=0,n, pollegendre(n-k, k)<<(n-k)) \\ _Charles R Greathouse IV_, Mar 19 2017
%K A110125 easy,nonn
%O A110125 0,4
%A A110125 _Paul Barry_, Jul 13 2005