A386975 a(n) is the permanent of the n X n matrix M_n with M_n(j,k) = j for j <> k, M_n(j,k) = n+j for j = k.

1, 2, 14, 183, 3792, 114780, 4807728, 267380071, 19098388480, 1705287529422, 186174804704000, 24402257980061599, 3781731531452940288, 684046276855242721368, 142823583210894978115584, 34092816821609506532859375, 9226267072346511233190461440, 2809774286001810901571097532538

Offset: 0

Author

Stefano Spezia, Aug 11 2025

Keywords

• nonn

Examples

			a(5) = permanent(M_5) = 114780 where M_5 is the matrix
  [6, 1, 1, 1,  1]
  [2, 7, 2, 2,  2]
  [3, 3, 8, 3,  3]
  [4, 4, 4, 9,  4]
  [5, 5, 5, 5, 10]
		

Crossrefs

Cf. A174962 (determinants), A386974.

Programs

Mathematica

M[j_,k_,n_]:=If[j!=k,j,If[j==k,n+j]]; a[n_]:=Permanent[Table[M[i,j,n],{i,n},{j,n}]];Join[{1}, Array[a,17]]

PARI

a(n) = matpermanent(matrix(n, n, j, k, if (j==k, n+j, j))); \\ Michel Marcus, Aug 12 2025