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A063241
Dimension of the space of weight 2n cuspidal newforms for Gamma_0(90).
3
3, 5, 7, 13, 15, 17, 23, 25, 27, 33, 35, 37, 43, 45, 47, 53, 55, 57, 63, 65, 67, 73, 75, 77, 83, 85, 87, 93, 95, 97, 103, 105, 107, 113, 115, 117, 123, 125, 127, 133, 135, 137, 143, 145, 147, 153, 155, 157, 163, 165
OFFSET
1,1
COMMENTS
The sequence lists the odd numbers ending with 3, 5 and 7. This follows from Mathar's generating function. - Bruno Berselli, Feb 16 2016
FORMULA
G.f.: 3*x -x^2*(-5-2*x-6*x^2+3*x^3) / ( (1+x+x^2)*(x-1)^2 ). - R. J. Mathar, Jul 15 2015
a(n) = 2*n + 4*floor(n/3 - 1/3) + 1. This formula follows from Mathar's generating function. - Bruno Berselli, Feb 16 2016
CROSSREFS
Cf. A063213.
Sequence in context: A361977 A285130 A024909 * A007591 A097687 A032911
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jul 10 2001
STATUS
approved