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 A321199 #8 Nov 14 2018 01:12:35
%S A321199 1,1,2,2,4,2,7,-5,16,-40,74,-196,431,-999,2433,-5575,13600,-32264,
%T A321199 77794,-188630,456078,-1113702,2716432,-6656382,16351231,-40236773,
%U A321199 99308252,-245471638,608083547,-1508944093,3750434282,-9336906118,23277132752,-58112501728,145266946742,-363574425058
%N A321199 Row sums of Riordan triangle A321198.
%C A321199 The alternating row sums of triangle A321198 are given in A321200.
%F A321199 a(n) = Sum_{k=0..n} A321198(n, k), n >= 0.
%F A321199 G.f.: f(x)/(1 - x*f(x)), with f(x) = F^{[-1]}(x)/x = Sum_{n >= 0}
%F A321199 (-1)^(n+1)*A001005(n)*x^n, where F^{[-1]}(x) is the compositional inverse of F(y) = y/(1 + y^2 - y^3) (see A077961 for F(y)/y).
%Y A321199 Cf. A001005, A077961, A321198, A321200.
%K A321199 sign,easy
%O A321199 0,3
%A A321199 _Wolfdieter Lang_, Nov 12 2018