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A015438
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Gaussian binomial coefficient [ n,12 ] for q=-13.
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12
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1, 21633936185161, 507029461102251552321630151, 11807441196984503845077844573952807835871, 275100402115798836253928241395289617394098490488956444, 6409295323626866454933457428954320223001885025904687118646704057084
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OFFSET
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12,2
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REFERENCES
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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.
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LINKS
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FORMULA
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a(n)=product_{i=1..12} ((-13)^(n-i+1)-1)/((-13)^i-1). - M. F. Hasler, Nov 03 2012
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MATHEMATICA
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PROG
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(Sage) [gaussian_binomial(n, 12, -13) for n in range(12, 17)] # Zerinvary Lajos, May 28 2009
(PARI) A015438(n, r=12, q=-13)=prod(i=1, r, (q^(n-i+1)-1)/(q^i-1)) \\ M. F. Hasler, Nov 03 2012
(Magma) r:=12; q:=-13; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Nov 06 2012
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CROSSREFS
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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), A015422 (r=11). - M. F. Hasler, Nov 03 2012
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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