A015355 Gaussian binomial coefficient [ n,7 ] for q=-13.
1, -58266480, 3677897920745140, -230677643550873536294640, 14475186854407942097510802411322, -908294062111964496034866469968025332240
Offset: 7
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
Crossrefs
Programs
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Magma
r:=7; q:=-13; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..15]]; // Vincenzo Librandi, Nov 02 2012
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Mathematica
Table[QBinomial[n, 7, -13], {n, 7, 16}] (* Vincenzo Librandi, Nov 02 2012 *)
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PARI
A015355(n,r=7,q=-13)=prod(i=1,r,(q^(n-i+1)-1)/(q^i-1)) \\ M. F. Hasler, Nov 03 2012
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Sage
[gaussian_binomial(n,7,-13) for n in range(7,13)] # Zerinvary Lajos, May 27 2009
Formula
a(n) = Product_{i=1..7} ((-13)^(n-i+1)-1)/((-13)^i-1). - M. F. Hasler, Nov 03 2012