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A022220
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Gaussian binomial coefficients [ n,2 ] for q = 6.
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2
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1, 43, 1591, 57535, 2072815, 74630671, 2686760143, 96723701071, 3482055254095, 125354001240655, 4512744117222991, 162458788655384143, 5848516394205967951, 210546590207087679055, 7579677247549193442895, 272868380912335185925711
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OFFSET
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2,2
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LINKS
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FORMULA
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G.f.: x^2/((1-x)*(1-6*x)*(1-36*x)).
a(n) = Product_{i=1..2} (6^(n-i+1)-1)/(6^i-1), by definition. - Vincenzo Librandi, Aug 16 2016
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MATHEMATICA
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PROG
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(Sage) [gaussian_binomial(n, 2, 6) for n in range(2, 17)] # Zerinvary Lajos, May 28 2009
(Magma) r:=2; q:=6; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 10 2016
(PARI) r=2; q=6; for(n=r, 30, print1(prod(j=1, r, (1-q^(n-j+1))/(1-q^j)), ", ")) \\ G. C. Greubel, Jun 07 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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