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 A361538 #8 Mar 19 2023 04:56:06
%S A361538 1,5,244,19090,1839075,199363606,23320604384,2876887986028,
%T A361538 369107300988219,48807370374419910,6610055144592717246,
%U A361538 912769451975745598299,128087096344387852459658,18219369599509083643661044,2621701165622760015979876800,381039123615762485580377457688
%N A361538 Central terms of triangle A361050.
%H A361538 Paul D. Hanna, <a href="/A361538/b361538.txt">Table of n, a(n) for n = 1..51</a>
%F A361538 a(n) = A361050(2*n-1,n-1) for n >= 1.
%F A361538 a(n) ~ c * d^n / n^2, where d = 166.5794571279985... and c = 0.000249393859904361... - _Vaclav Kotesovec_, Mar 19 2023
%o A361538 (PARI) {A361050(n,k) = my(A=[0, 1]); for(i=1, n, A = concat(A, 0);
%o A361538 A[#A] = polcoeff(y/x - prod(m=1, #A, (1 - x^m) * (1 - x^m*Ser(A)) * (1 - x^(m-1)/Ser(A)) * (1 - x^(2*m-1)*Ser(A)^2) * (1 - x^(2*m-1)/Ser(A)^2) ), #A-4) );
%o A361538 polcoeff(polcoeff(H=Ser(A),n,x),k,y)}
%o A361538 for(n=1, 16, print1(A361050(2*n-1,n-1), ", "))
%Y A361538 Cf. A361050.
%K A361538 nonn
%O A361538 1,2
%A A361538 _Paul D. Hanna_, Mar 18 2023