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A022232
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Gaussian binomial coefficients [ n,3 ] for q = 7.
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1
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1, 400, 140050, 48177200, 16531644851, 5670690600800, 1945063360640100, 667157540444234400, 228835075951868449701, 78490432990886231801200, 26922218610904350161500150, 9234320988196680367732171600
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OFFSET
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3,2
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LINKS
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FORMULA
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G.f.: x^3/((1-x)*(1-7*x)*(1-49*x)*(1-343*x)).
a(n) = Product_{i=1..3} (7^(n-i+1)-1)/(7^i-1), by definition. - Vincenzo Librandi, Aug 06 2016
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MATHEMATICA
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PROG
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(Sage) [gaussian_binomial(n, 3, 7) for n in range(3, 15)] # Zerinvary Lajos, May 27 2009
(Magma) r:=3; q:=7; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 06 2016
(PARI) r=3; q=7; for(n=r, 30, print1(prod(j=1, r, (1-q^(n-j+1))/(1-q^j)), ", ")) \\ G. C. Greubel, Jun 13 2018
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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