OFFSET
7,2
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 = 7..160
FORMULA
a(n) = Product_{i=1..7} (8^(n-i+1)-1)/(8^i-1), by definition. - Vincenzo Librandi, Aug 06 2016
G.f.: x^7/((1 - x)*(1 - 8*x)*(1 - 64*x)*(1 - 512*x)*(1 - 4096*x)*(1 - 32768*x)*(1 - 262144*x)*(1 - 2097152*x)). - Ilya Gutkovskiy, Aug 06 2016
MATHEMATICA
Table[QBinomial[n, 7, 8], {n, 7, 20}] (* Vincenzo Librandi, Aug 06 2016 *)
PROG
(Sage) [gaussian_binomial(n, 7, 8) for n in range(7, 16)] # Zerinvary Lajos, May 27 2009
(Magma) r:=7; q:=8; [&*[(1-q^(n-i+1))/(1-q^i): i in [1..r]]: n in [r..20]]; // Vincenzo Librandi, Aug 06 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Offset changed by Vincenzo Librandi, Aug 06 2016
STATUS
approved