A278926 a(n) = permanent M_n where M_n is the n X n matrix m(i,j) = i^4 + j^4.

1, 2, 353, 561608, 4341274884, 111107400842568, 7493918659070379300, 1139021252689549522419840, 348457223545199873458486125120, 196982631587037086047232203674775680, 192443334239172066295878807351087122210880, 307899710379447999264505625949360598523097530880

Offset: 0

Author

Vaclav Kotesovec, Dec 01 2016

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..36

Crossrefs

Cf. A204249, A278847, A278925.

Programs

Maple

with(LinearAlgebra):
a:= n-> `if`(n=0, 1, Permanent(Matrix(n, (i, j)-> i^4+j^4))):
seq(a(n), n=0..16);

Mathematica

Flatten[{1, Table[Permanent[Table[i^4+j^4, {i, 1, n}, {j, 1, n}]], {n, 1, 15}]}]

PARI

{a(n) = matpermanent(matrix(n, n, i, j, i^4+j^4))}
for(n=0, 20, print1(a(n), ", ")) \\ Vaclav Kotesovec, Dec 21 2018

Formula

a(n) ~ c * d^n * n!^5 / n^2, where d = 11.83108... and c = 0.68284...