OFFSET
1,1
LINKS
William A. Stein, Dimensions of the spaces S_k(Gamma_0(N)).
William A. Stein, The modular forms database
FORMULA
Conjecture: a(n) = ((-1)^n+30*n-17)/2 for n>1. a(n) = a(n-1)+a(n-2)-a(n-3) for n>4. G.f.: x*(7+15*x+7*x^2+x^3)/((1-x)^2*(1+x)). [Colin Barker, Sep 26 2012]
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 08 2001
STATUS
approved