cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A022199 Gaussian binomial coefficients [ n,8 ] for q = 3.

Original entry on oeis.org

1, 9841, 72636421, 494894285941, 3287582741506063, 21658948312410865183, 142299528422960399756323, 934054234760012359481199283, 6129263888495201102915629695046, 40216143252770054194345243936096486, 263862583736385343242102717216527933566
Offset: 8

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References

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

Programs

  • Magma
    r:=8; q:=3; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 07 2016
    
  • Mathematica
    Table[QBinomial[n, 8, 3], {n, 8, 20}] (* Vincenzo Librandi, Aug 07 2016 *)
  • PARI
    r=8; q=3; for(n=r,30, print1(prod(j=1,r,(1-q^(n-j+1))/(1-q^j)), ", ")) \\ G. C. Greubel, May 30 2018
  • Sage
    [gaussian_binomial(n,8,3) for n in range(8,19)] # Zerinvary Lajos, May 25 2009
    

Formula

G.f.: x^8/((1-x)*(1-3*x)*(1-9*x)*(1-27*x)*(1-81*x)*(1-243*x)*(1-729*x)*(1-2187*x)*(1-6561*x)). - Vincenzo Librandi, Aug 07 2016
a(n) = Product_{i=1..8} (3^(n-i+1)-1)/(3^i-1), by definition. - Vincenzo Librandi, Aug 07 2016

Extensions

Offset changed by Vincenzo Librandi, Aug 07 2016