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A015375 Gaussian binomial coefficient [ n,9 ] for q=-3. 13
1, -14762, 326882347, -6204226946060, 123644349019377043, -2423717068608654822146, 47771556642163840723529281, -939857780045414554730512966640, 18502040831058043147238631145734166, -364157167636884405223950738210339855212 (list; graph; refs; listen; history; text; internal format)
OFFSET

9,2

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 = 9..200

FORMULA

a(n) = product(((-3)^(n-i+1)-1)/((-3)^i-1), i=1..9) (by definition). - Vincenzo Librandi, Nov 04 2012

MATHEMATICA

Table[QBinomial[n, 9, -3], {n, 9, 20}] (* Vincenzo Librandi, Nov 04 2012 *)

PROG

(Sage) [gaussian_binomial(n, 9, -3) for n in xrange(9, 18)] # [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), May 25 2009]

(MAGMA) r:=9; q:=-3; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Nov 04 2012

CROSSREFS

Cf. Gaussian binomial coefficients [n,9] for q=-2,...,-13: A015371, A015376, A015377, A015378, A015379, A015380, A015381, A015382, A015383, A015384, A015385. - Vincenzo Librandi, Nov 04 2012

Sequence in context: A178588 A089315 A202314 * A043648 A035919 A186790

Adjacent sequences:  A015372 A015373 A015374 * A015376 A015377 A015378

KEYWORD

sign,easy

AUTHOR

Olivier Gérard

STATUS

approved

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Last modified May 24 14:15 EDT 2013. Contains 225622 sequences.