OFFSET
1,2
LINKS
Lara Pudwell, Systematic Studies in Pattern Avoidance, 2005.
Index entries for linear recurrences with constant coefficients, signature (7,-20,30,-25,11,-2).
FORMULA
G.f.: x*(1 - 5*x + 11*x^2 - 11*x^3 + 8*x^4 - 2*x^5) / ((1 - x)^5*(1 - 2*x)).
a(n) = 5*2^n-(n+2)*(n^3+11*n+24)/12. - R. J. Mathar, Jan 12 2013
PROG
(PARI) Vec(x*(1 - 5*x + 11*x^2 - 11*x^3 + 8*x^4 - 2*x^5) / ((1 - x)^5*(1 - 2*x)) + O(x^40)) \\ Colin Barker, Nov 01 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Lara Pudwell, Feb 26 2006
STATUS
approved