OFFSET
2,2
LINKS
William A. Stein, Dimensions of the spaces S_k^{new}(Gamma_1(N))
William A. Stein, The modular forms database
FORMULA
From Colin Barker, Feb 24 2015: (Start)
a(n) = a(n-2)+a(n-4)-a(n-6) for n>8.
G.f.: x^2*(x^6+9*x^5+15*x^4+12*x^3+13*x^2+5*x-1) / ((x-1)^2*(x+1)^2*(x^2+1)).
(End)
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Jul 14 2001
STATUS
approved