OFFSET
9,2
REFERENCES
F. J. MacWilliams and N. J. A. Sloane, The Theory of Error-Correcting Codes, Elsevier-North Holland, 1978, p. 698.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 9..120
FORMULA
a(n) = Product_{i=1..9} (9^(n-i+1)-1)/(9^i-1), by definition. - Vincenzo Librandi, Aug 04 2016
G.f.: x^9/((1 - x)*(1 - 9*x)*(1 - 81*x)*(1 - 729*x)*(1 - 6561*x)*(1 - 59049*x)*(1 - 531441*x)*(1 - 4782969*x)*(1 - 43046721*x)*(1 - 387420489*x)). - Ilya Gutkovskiy, Aug 04 2016
MATHEMATICA
Drop[QBinomial[Range[20], 9, 9], 8] (* Harvey P. Dale, May 30 2012 *)
Table[QBinomial[n, 9, 9], {n, 9, 20}] (* Vincenzo Librandi, Aug 04 2016 *)
PROG
(Sage) [gaussian_binomial(n, 9, 9) for n in range(9, 15)] # Zerinvary Lajos, May 25 2009
(Magma) r:=9; q:=9; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 04 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
One additional term from Harvey P. Dale, May 30 2012
STATUS
approved