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A063089
Dimension of the space of weight 2n cusp forms for Gamma_0( 21 ).
0
1, 6, 12, 16, 22, 28, 32, 38, 44, 48, 54, 60, 64, 70, 76, 80, 86, 92, 96, 102, 108, 112, 118, 124, 128, 134, 140, 144, 150, 156, 160, 166, 172, 176, 182, 188, 192, 198, 204, 208, 214, 220, 224, 230, 236, 240, 246, 252, 256, 262
OFFSET
1,2
FORMULA
Conjectures from Colin Barker, Jun 09 2019: (Start)
G.f.: x*(1 + x)*(1 + 4*x + 2*x^2 + x^3) / ((1 - x)^2*(1 + x + x^2)).
a(n) = a(n-1) + a(n-3) - a(n-4) for n>5.
(End)
CROSSREFS
Sequence in context: A315647 A315648 A315649 * A315650 A315651 A315652
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 08 2001
STATUS
approved