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

1,3

Comments

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

Links

Table of n, a(n) for n=1..21.

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

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

Crossrefs

Cf. A000271.

Sequence in context: A087570 A124221 A339415 * A371133 A010743 A072032

Adjacent sequences: A097622 A097623 A097624 * A097626 A097627 A097628

Keyword

sign

Author

Ralf Stephan, Sep 20 2004

Status

approved