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A030509
Graham-Sloane-type lower bound on the size of a ternary (n,3,9) constant-weight code.
0
27, 244, 1225, 4506, 13559, 35346, 82664, 177494, 355621, 672796, 1212758, 2097452, 3499818, 5659535, 8902155, 13662083, 20509867, 30184333, 43630080, 62040927, 86909874, 120086243, 163840610, 220938240, 294721720, 389203523, 509169290, 660292594, 849262046
OFFSET
9,1
LINKS
M. Svanstrom, A lower bound for ternary constant weight codes, IEEE Trans. on Information Theory, Vol. 43, pp. 1630-1632, Sep. 1997.
FORMULA
a(n) = ceiling(binomial(n, w) * 2^w / (2*n + 1)) with w=9.
CROSSREFS
Sequence in context: A075548 A345054 A074117 * A042414 A099226 A016107
KEYWORD
nonn
AUTHOR
Mattias Svanstrom (mattias(AT)isy.liu.se)
STATUS
approved