OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
A. Prasad, Equivalence classes of nodes in trees and rational generating functions, arXiv preprint arXiv:1407.5284 [math.CO], 2014
Index entries for linear recurrences with constant coefficients, signature (18,-121,372,-508,240).
FORMULA
a(n) = (1 - 3*2^(2+n) + 7*2^(1+2*n) + 3*5^n + 6^(1+n)) / 12. - Colin Barker, Jun 06 2015
PROG
(PARI) Vec((2*x^4-21*x^3+34*x^2-11*x+1)/(-240*x^5+508*x^4-372*x^3+121*x^2-18*x+1) + O(x^40)) \\ Colin Barker, Jun 06 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Sep 15 2014
STATUS
approved