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 A091753 #10 Sep 01 2025 03:06:20 %S A091753 1,60,6720,1232000,336336000,128076748800,64892219392000, %T A091753 42217023873024000,34301331896832000000,34042166278055936000000, %U A091753 40523794737397786214400000,56991191326140341157888000000,93484550838645539612655616000000,176901534663898482651640627200000000 %N A091753 Fourth column (m=5) of array A091752 ((-1,2)Stirling2) divided by -6. %F A091753 a(n) = -A091752(n, 5)/6, n>=3. %F A091753 a(n) = ((n-1)*(n-2)/4)*(3*(n-2))!/((3^(n-2))*(n-2)!) = ((n-1)*(n-2)/4)*A052502(n-2), n>=3. %F A091753 G.f.: (x^3)*hypergeom([4/3, 5/3, 3], [], 9*x). %F A091753 a(n) ~ 3^(2*n-7/2) * n^(2*n-2) / (4 * exp(2*n-5/n)). - _Amiram Eldar_, Sep 01 2025 %t A091753 a[n_] := ((n-1)*(n-2)/4) * (3*(n-2))!/((3^(n-2))*(n-2)!); Array[a, 20, 3] (* _Amiram Eldar_, Sep 01 2025 *) %Y A091753 Cf. A052502, A091752. %K A091753 nonn,easy,changed %O A091753 3,2 %A A091753 _Wolfdieter Lang_, Feb 27 2004