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 A321200 #6 Nov 14 2018 01:12:29
%S A321200 1,-1,2,-4,8,-18,39,-89,204,-472,1110,-2616,6231,-14909,35861,-86705,
%T A321200 210364,-512480,1252350,-3069638,7544818,-18589202,45907708,
%U A321200 -113608590,281698359,-699748003,1741102844,-4338995332,10828981851,-27063384783,67722954114,-169674183372,425590855116,-1068654838488
%N A321200 Alternating row sums of Riordan triangle A321198.
%C A321200 The row sums of triangle A321198 are given in A321199.
%F A321200 a(n) = Sum_{k=0..n} A321198(n, k), n >= 0.
%F A321200 G.f.: f(x)/(1 + x*f(x)), with f(x) = F^{[-1]}(x)/x = Sum_{n >= 0} (-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 A321200 Cf. A001005, A077961, A321198, A321199.
%K A321200 sign,easy
%O A321200 0,3
%A A321200 _Wolfdieter Lang_, Nov 12 2018