OFFSET
0,23
LINKS
Vaclav Kotesovec, Table of n, a(n) for n = 0..10000
FORMULA
G.f.: 1/product(1-x^(4+7j), j=0..infinity). - Emeric Deutsch, Apr 14 2006
a(n) ~ Gamma(4/7) * exp(Pi*sqrt(2*n/21)) / (2^(25/14) * 3^(2/7) * 7^(3/14) * Pi^(3/7) * n^(11/14)) * (1 + (23*Pi/(168*sqrt(42)) - 11*sqrt(6/7)/(7*Pi)) / sqrt(n)). - Vaclav Kotesovec, Feb 27 2015, extended Jan 24 2017
a(n) = (1/n)*Sum_{k=1..n} A284445(k)*a(n-k), a(0) = 1. - Seiichi Manyama, Mar 28 2017
EXAMPLE
a(22)=2 because we have 22=18+4=11+11.
MAPLE
g:=1/product(1-x^(4+7*j), j=0..20): gser:=series(g, x=0, 93): seq(coeff(gser, x, n), n=0..90); # Emeric Deutsch, Apr 14 2006
MATHEMATICA
nmax=100; CoefficientList[Series[Product[1/(1-x^(7*k+4)), {k, 0, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Feb 27 2015 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Erich Friedman, Aug 07 2005
EXTENSIONS
Changed offset to 0 and added a(0)=1 by Vaclav Kotesovec, Feb 27 2015
STATUS
approved