OFFSET
0,2
REFERENCES
P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 160, Sigma(Gamma_10, S_10; z).
LINKS
Colin Barker, Table of n, a(n) for n = 0..600
Index entries for linear recurrences with constant coefficients, signature (39,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,-39,1).
FORMULA
G.f.: (1+x)*(1-x^20)/(1-39*x+39*x^20-x^21).
PROG
(PARI) Vec((1+x)*(1-x^20)/(1-39*x+39*x^20-x^21) + O(x^15)) \\ Colin Barker, Jun 13 2019
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
N. J. A. Sloane, Aug 21 2001
STATUS
approved