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A015427
Gaussian binomial coefficient [ n,12 ] for q=-5.
2
1, 203450521, 51740143068101671, 12531617923263572089314671, 3064380040090865325461356053952796, 747900330120650910670378436164144443652796, 182604540723920504029015495725080327984747417027796, 44580616068292567497216163076570130750072904955316534527796
OFFSET
12,2
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
FORMULA
a(n) = Product_{i=1..12} ((-5)^(n-i+1)-1)/((-5)^i-1). - Vincenzo Librandi, Nov 06 2012
MATHEMATICA
QBinomial[Range[12, 20], 12, -5] (* Harvey P. Dale, Mar 28 2012 *)
Table[QBinomial[n, 12, -5], {n, 12, 20}] (* Vincenzo Librandi, Nov 06 2012 *)
PROG
(Sage) [gaussian_binomial(n, 12, -5) for n in range(12, 18)] # Zerinvary Lajos, May 28 2009
(Magma) r:=12; q:=-5; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Nov 06 2012
CROSSREFS
Sequence in context: A317287 A132205 A358019 * A078249 A243363 A273094
KEYWORD
nonn,easy
EXTENSIONS
More terms from Harvey P. Dale, Mar 28 2012
STATUS
approved