A325052 a(n) = Product_{i=0..n, j=0..n, k=0..n} (i! + j! + k!).

3, 6561, 10319560704000000, 47749397192482757629144508002855841842593792000000000

Offset

0,1

Comments

Next term is too long to be included.

Links

Table of n, a(n) for n=0..3.

Formula

a(n) ~ c * 2^(n^3/2 + 3*n^2 + 3*n) * 3^n * Pi^(n^3/2 + 3*n^2/2 + 3*n/2) * n^(3*n^4/4 + 3*n^3 + 17*n^2/4 + 5*n/2 + 601/120) / exp(15*n^4/16 + 3*n^3 + 3*n^2 - 21*n/4), where c = 28023.0953536911860317693532637428153075420958129597133...

Mathematica

Table[Product[i! + j! + k!, {i, 0, n}, {j, 0, n}, {k, 0, n}], {n, 0, 5}]
Clear[a]; a[n_] := a[n] = If[n == 0, 3, a[n-1] * Product[k! + j! + n!, {j, 0, n}, {k, 0, n}]^3 * (3*n!) / (Product[k! + 2*n!, {k, 0, n}]^3)]; Table[a[n], {n, 0, 5}]

Crossrefs

Cf. A306594, A306729, A324425, A325053.

Sequence in context: A185671 A338412 A187879 * A283019 A056749 A281788

Adjacent sequences: A325049 A325050 A325051 * A325053 A325054 A325055

Keyword

nonn

Author

Vaclav Kotesovec, Mar 26 2019

Status

approved