1,2

Table of n, a(n) for n=1..50.

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 (1,0,1,-1).

G.f.: x +2*x^2*(1+x) / ( (1+x+x^2)*(x-1)^2 ). - R. J. Mathar, Jul 15 2015

Sequence in context: A186690 A002131 A230641 * A063224 A023847 A279667

Adjacent sequences: A063197 A063198 A063199 * A063201 A063202 A063203

nonn

N. J. A. Sloane, Jul 10 2001

approved