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 A169619 #9 Jan 23 2024 07:40:37
%S A169619 1,4,640,11059200,39749419008000,48575443603606732800000,
%T A169619 29918051262318914110928977920000000,
%U A169619 12898757220773940360062849214160935321600000000000
%N A169619 Hankel transform of quartic (or 4-fold) factorial numbers A007696.
%F A169619 a(n) = Product_{k=0..n} ((4*k+1)*(4*k+4))^(n-k).
%F A169619 a(n) ~ 2^(2*n^2 + 3*n + 5/8) * Pi^(n + 5/8) * n^(n^2 + 5*n/4 + 35/96) / (A^(7/8) * Gamma(1/4)^(n + 1/4) * exp(3*n^2/2 + 5*n/4 - 7/96 - G/(4*Pi))), where G is Catalan's constant A006752 and A is the Glaisher-Kinkelin constant A074962. - _Vaclav Kotesovec_, Jan 23 2024
%t A169619 Table[Product[((4*k+1)*(4*k+4))^(n-k), {k,0,n}], {n,0,10}] (* _Vaclav Kotesovec_, Jan 23 2024 *)
%Y A169619 Cf. A007696.
%K A169619 easy,nonn
%O A169619 0,2
%A A169619 _Paul Barry_, Dec 03 2009