OFFSET
0,2
REFERENCES
P. de la Harpe, Topics in Geometric Group Theory, Univ. Chicago Press, 2000, p. 160, Sigma(Gamma_6, S_6; z).
LINKS
Colin Barker, Table of n, a(n) for n = 0..700
Index entries for linear recurrences with constant coefficients, signature (23,0,0,0,0,0,0,0,0,0,0,-23,1).
FORMULA
G.f.: (1+x)*(1-x^12)/(1-23*x+23*x^12-x^13).
a(n) = 23*a(n-1) - 23*a(n-12) + a(n-13) for n>13. - Colin Barker, Jun 13 2019
PROG
(PARI) Vec((1+x)*(1-x^12)/(1-23*x+23*x^12-x^13) + O(x^20)) \\ Colin Barker, Jun 13 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Aug 21 2001
STATUS
approved