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A015422
Gaussian binomial coefficient [ n,11 ] for q=-13.
12
1, -1664148937320, 3000174326048697741925710, -5374347381421937558314402513609688760, 9632029764916740618771445568833182996026908640493, -17262095767026556801586191040816999767731925288888540910160480
OFFSET
11,2
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.
FORMULA
a(n) = Product_{i=1..11} ((-13)^(n-i+1)-1)/((-13)^i-1). - M. F. Hasler, Nov 03 2012
MATHEMATICA
Table[QBinomial[n, 11, -13], {n, 11, 20}] (* Vincenzo Librandi, Nov 06 2012 *)
PROG
(Sage) [gaussian_binomial(n, 11, -13) for n in range(11, 16)] # Zerinvary Lajos, May 28 2009
(PARI) A015422(n, r=11, q=-13)=prod(i=1, r, (q^(n-i+1)-1)/(q^i-1)) \\ M. F. Hasler, Nov 03 2012
(Magma) r:=11; q:=-13; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Nov 06 2012
CROSSREFS
Cf. Gaussian binomial coefficients [n,r] for q=-13: A015265 (r=2), A015286 (r=3), A015303 (r=4), A015321 (r=5), A015337 (r=6), A015355 (r=7), A015370 (r=8), A015385 (r=9), A015402 (r=10), A015438 (r=12). - M. F. Hasler, Nov 03 2012
Sequence in context: A320943 A248892 A172799 * A289148 A282182 A017543
KEYWORD
sign,easy
STATUS
approved