A015356 Gaussian binomial coefficient [ n,8 ] for q=-2.

1, 171, 58311, 13275471, 3624203583, 899790907743, 233988483199263, 59438516325245343, 15275698695588053151, 3902985682508407194271, 1000137219716325891620511, 255910660218571393553843871

Offset

8,2

References

J. Goldman and G.-C. Rota, The number of subspaces of a vector space, pp. 75-83 of W. T. Tutte, editor, Recent Progress in Combinatorics. Academic Press, NY, 1969.

I. P. Goulden and D. M. Jackson, Combinatorial Enumeration. Wiley, NY, 1983, p. 99.

M. Sved, Gaussians and binomials, Ars. Combinatoria, 17A (1984), 325-351.

Links

Vincenzo Librandi, Table of n, a(n) for n = 8..200

Index entries for linear recurrences with constant coefficients, signature (171,29070,-1666680,-56000448,896007168,6826721280,-30482104320,-45902462976,68719476736).

Formula

a(n) = Product_{i=1..8} ((-2)^(n-i+1)-1)/((-2)^i-1). - M. F. Hasler, Nov 03 2012

G.f.: -x^8 / ( (x-1)*(64*x-1)*(128*x+1)*(2*x+1)*(8*x+1)*(32*x+1)*(16*x-1)*(4*x-1)*(256*x-1) ). - R. J. Mathar, Sep 02 2016

Mathematica

Table[QBinomial[n, 8, -2], {n, 8, 20}] (* Vincenzo Librandi, Nov 02 2012 *)

Prog

(Sage) [gaussian_binomial(n, 8, -2) for n in range(8, 20)] # Zerinvary Lajos, May 25 2009
(Magma) r:=8; q:=-2; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..25]]; // Vincenzo Librandi, Nov 02 2012
(PARI) A015356(n, r=8, q=-2)=prod(i=1, r, (q^(n-i+1)-1)/(q^i-1)) \\ M. F. Hasler, Nov 03 2012

Crossrefs

Cf. Gaussian binomial coefficients [n,8] for q=-3..-13: A015357, A015359, A015360, A015361, A015363, A015364, A015365, A015367, A015368, A015369, A015370. - M. F. Hasler, Nov 03 2012

Diagonal k=8 of the triangular array A015109. See there for further references and programs. - M. F. Hasler, Nov 04 2012

Sequence in context: A145625 A097844 A076573 * A259158 A252139 A252132

Adjacent sequences: A015353 A015354 A015355 * A015357 A015358 A015359

Keyword

nonn,easy

Author

Olivier Gérard

Status

approved