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Gaussian binomial coefficients [ n,9 ] for q = 5.
1

%I #20 Sep 08 2022 08:44:46

%S 1,2441406,4967053120931,9779511680526143556,

%T 19131218685276848401412931,37377622327704219905090668384806,

%U 73007841108236063781239140920167306681,142595264882979563844964491038787206333791056

%N Gaussian binomial coefficients [ n,9 ] for q = 5.

%D F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier-North Holland, 1978, p. 698.

%H Vincenzo Librandi, <a href="/A022216/b022216.txt">Table of n, a(n) for n = 9..170</a>

%F G.f.: x^9/((1-x)*(1-5*x)*(1-25*x)*(1-125*x)*(1-625*x)*(1-3125*x)*(1-15625*x)*(1-78125*x)*(1-390625*x)*(1-1953125*x)). - _Vincenzo Librandi_, Aug 10 2016

%F a(n) = Product_{i=1..9} (5^(n-i+1)-1)/(5^i-1), by definition. - _Vincenzo Librandi_, Aug 10 2016

%t Table[QBinomial[n, 9, 5], {n, 9, 20}] (* _Vincenzo Librandi_, Aug 10 2016 *)

%o (Sage) [gaussian_binomial(n,9,5) for n in range(9,16)] # _Zerinvary Lajos_, May 25 2009

%o (Magma) r:=9; q:=5; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // _Vincenzo Librandi_, Aug 10 2016

%o (PARI) r=9; q=5; for(n=r,30, print1(prod(j=1,r,(1-q^(n-j+1))/(1-q^j)), ", ")) \\ _G. C. Greubel_, Jun 07 2018

%K nonn,easy

%O 9,2

%A _N. J. A. Sloane_

%E Offset changed by _Vincenzo Librandi_, Aug 10 2016