A086647 Number of monomials in expansion of permanent of an n X n Toeplitz matrix [t(|i-j|) ] in terms of its entries.

1, 2, 4, 12, 36, 128, 460, 1750, 6551, 25108, 94977, 363533, 1378573, 5273561

Offset: 1

Author

Yuval Dekel (dekelyuval(AT)hotmail.com), Jul 26 2003

Keywords

• nonn

Crossrefs

Cf. A019447, A019448, A019589.

Programs

Maple

with(LinearAlgebra): f:=n->nops([coeffs(Permanent(Matrix(n, (i, j) -> a[abs(i-j)])))]): [seq(f(n), n=1..12)]; # Vaclav Kotesovec, Mar 29 2019

Mathematica

Permanent[m_List] := With[{v = Array[x, Length@m]}, Coefficient[Times @@ (m . v), Times @@ v]]; ; f[n_] := Length@Expand@Permanent@Table[t[Abs[i - j]], {i, n}, {j, n}]; Array[f, 11] (* Robert G. Wilson v *)

Extensions

More terms from Robert G. Wilson v, Sep 22 2006

a(12) from Vaclav Kotesovec, Mar 20 2019

a(13)-a(14) from Vaclav Kotesovec, Mar 29 2019