A204234 Permanent of the n-th principal submatrix of A203990.

1, 2, 25, 1018, 97617, 18239786, 5881589105, 3009156161810, 2296768410595849, 2494959953768765810, 3716590842220109346457, 7367123790912343973015562, 18955419073428722394855382209, 61999496577719659890376379418138, 253245883804141341597229595842097313

Offset: 0

Author

Clark Kimberling, Jan 13 2012

Keywords

• nonn

Crossrefs

Cf. A203990.

Programs

Maple

with(LinearAlgebra):
a:= n-> `if`(n=0, 1, Permanent(Matrix(n, (i, j)-> (i+j)*min(i, j)))):
seq(a(n), n=0..16);  # Alois P. Heinz, Nov 14 2016

Mathematica

f[i_, j_] := (i + j) Min[i, j];  (* A203990 *)
m[n_] := Table[f[i, j], {i, 1, n}, {j, 1, n}]
Table[Det[m[n]], {n, 1, 22}]  (* A114160 *)
Permanent[m_] :=
  With[{a = Array[x, Length[m]]},
   Coefficient[Times @@ (m.a), Times @@ a]];
Table[Permanent[m[n]], {n, 1, 14}]  (* A204234 *)

Extensions

a(0)=1 prepended and one more term added by Alois P. Heinz, Nov 14 2016