A097625 a(n) = Sum_{k=0..n} (-2)^k * binomial(2n-k,k) * (n-k)!.

-1, 0, 2, -4, 8, 0, 80, 544, 5248, 53504, 601344, 7339520, 96797696, 1371889664, 20797212672, 335835828224, 5755617771520, 104346351861760, 1995288143593472, 40135085601325056, 847203499270995968

Offset: 1

Author

Ralf Stephan, Sep 20 2004

Keywords

• sign

Comments

Permanent of certain n X 2 Toeplitz-(1,-1) matrices.

Links

• A. R. Kräuter, Über die Permanente gewisser zirkulärer Matrizen..., Sem. Loth. Combin. B11b (1984) 82-94

Crossrefs

Cf. A000271.

Programs

Maple

A097625 := proc(n) add((-2)^k*(n-k)!*binomial(2*n-k,k),k=0..n) ; end proc:
seq(A097625(n),n=1..30) ; # R. J. Mathar, Sep 18 2011