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 A218503 #28 Feb 14 2024 09:08:58 %S A218503 1,120,9765,251680,3043425,22661496,121226245,510902400,1799118945, %T A218503 5507702200,15072415941,37630041120,87029433985,188664603960, %U A218503 386925380325,756298318336,1417430759745,2559798038520,4472991338725,7589075296800,12538953723681 %N A218503 q-factorial numbers 5!_q. %H A218503 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a> %H A218503 <a href="/index/Rec#order_11">Index entries for linear recurrences with constant coefficients</a>, signature (11,-55,165,-330,462,-462,330,-165,55,-11,1). %F A218503 a(n) = (n + 1)*(n^2 + n + 1)*(n^3 + n^2 + n + 1)*(n^4 + n^3 + n^2 + n + 1). %F A218503 G.f.: (1 + x*(109 + x*(8500 + x*(150700 + x*(792550 + x*(1454134 + x*(978436 + 5*x*(45788 + x*(3053 + 33*x)))))))))/(1 - x)^11. %t A218503 Table[QFactorial[5, n], {n, 0, 20}] %t A218503 Join[{1},With[{f=Times@@Table[Total[n^Range[0,i]],{i,4}]},Table[f,{n,20}]]] (* or *) LinearRecurrence[{11,-55,165,-330,462,-462,330,-165,55,-11,1},{1,120,9765,251680,3043425,22661496,121226245,510902400,1799118945,5507702200,15072415941},30] (* _Harvey P. Dale_, Sep 04 2017 *) %Y A218503 Cf. A069777, A069778, A069779. %K A218503 easy,nonn %O A218503 0,2 %A A218503 _Arkadiusz Wesolowski_, Oct 31 2012