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A015312
Gaussian binomial coefficient [ n,5 ] for q = -7.
4
1, -14706, 252313293, -4228301370600, 71094673339606302, -1194817080145423511412, 20081461365765141084602686, -337508711324786004755672161800, 5672509895284807570626050787828903
OFFSET
5,2
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
Index entries for linear recurrences with constant coefficients, signature (-14706,36046857,12322995300,-605839525599,-4154081011794,4747561509943).
FORMULA
G.f.: -x^5 / ( (x-1)*(16807*x+1)*(49*x-1)*(343*x+1)*(7*x+1)*(2401*x-1) ). - R. J. Mathar, Aug 04 2016
MATHEMATICA
QBinomial[Range[5, 20], 5, -7] (* Harvey P. Dale, Feb 27 2012 *)
PROG
(Sage) [gaussian_binomial(n, 5, -7) for n in range(5, 14)] # Zerinvary Lajos, May 27 2009
(Magma) r:=5; q:=-7; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..25]]; // Vincenzo Librandi, Aug 03 2016
CROSSREFS
Sequence in context: A013861 A291145 A256839 * A219068 A023333 A249464
KEYWORD
sign,easy
AUTHOR
Olivier Gérard, Dec 11 1999
STATUS
approved