OFFSET
1,2
LINKS
D. Callan, T. Mansour, Enumeration of small Wilf classes avoiding 1324 and two other 4-letter patterns, arXiv:1705.00933 (2017), Table 2 No 68.
Lara Pudwell, Systematic Studies in Pattern Avoidance, 2005.
Index entries for linear recurrences with constant coefficients, signature (9,-33,63,-66,36,-8).
FORMULA
G.f.: A(x) = {x(3x^6-12x^5+22x^4-30x^3+21x^2-7x+1)}/{(2x-1)^3(x-1)^3}
a(n)=2^n*(-99/16+29n/32+3n^2/32)+n^2+4n+6, n>1. [From R. J. Mathar, Aug 05 2008]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Lara Pudwell, Feb 26 2006
STATUS
approved