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 A129278 #9 Feb 16 2025 08:33:05
%S A129278 1,8,106,1558,23589,360499,5530445,85040656,1310211074,20223812711,
%T A129278 312728963211,4844238210807,75161494829564,1167972975649534,
%U A129278 18175688264003359,283219807758089612,4418626917709277371
%N A129278 Column 2 of triangle A129276; a(n) is the coefficient of q^(2n+2) in the squared q-factorial of n+2.
%H A129278 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/q-Factorial.html">q-Factorial</a>.
%F A129278 a(n) = [q^(2n+2)] Product_{i=1..n+2} { (1-q^i)/(1-q) }^2.
%o A129278 (PARI) a(n)=polcoeff(prod(i=1,n+2,(1-x^i)/(1-x))^2,2*n+2)
%Y A129278 Cf. A129276, A129277.
%K A129278 nonn
%O A129278 0,2
%A A129278 _Paul D. Hanna_, Apr 07 2007