A015385 Gaussian binomial coefficient [ n,9 ] for q=-13.
1, -9847035132, 105044442632566365137, -1113436927250681654567602842120, 11807854622717155763702496765310830475383, -125216049699851612689080581288579246248342359563916
Offset: 9
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:=9; q:=-13; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Nov 04 2012
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Mathematica
Table[QBinomial[n, 9, -13],{n, 9, 20}] (* Vincenzo Librandi, Nov 04 2012 *)
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PARI
A015385(n,r=9,q=-13)=prod(i=1,r,(q^(n-i+1)-1)/(q^i-1)) \\ M. F. Hasler, Nov 03 2012
Formula
a(n) = Product_{i=1..9} ((-13)^(n-i+1)-1)/((-13)^i-1). - M. F. Hasler, Nov 03 2012