OFFSET
1,2
LINKS
R. J. Mathar, Table of n, a(n) for n = 1..1000
G. Martin, Dimensions of the spaces of cusp forms and newforms on Gamma_0(N) and Gamma_1(N), J. Numb. Theory 112 (2005) 298-331, Theorem 1.
William A. Stein, Dimensions of the spaces S_k^{new}(Gamma_0(N))
William A. Stein, The modular forms database
Index entries for linear recurrences with constant coefficients, signature (0,1,1,0,-1).
FORMULA
G.f.: x -2*x^2*(-1-2*x-2*x^2-x^3+x^4) / ( (1+x)*(1+x+x^2)*(x-1)^2 ). - R. J. Mathar, Jul 15 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 10 2001
STATUS
approved