OFFSET
1,2
LINKS
D. Callan, T. Mansour, Enumeration of small Wilf classes avoiding 1324 and two other 4-letter patterns, arXiv:1705.00933 [math.CO] (2017), Table 2 No 91.
Lara Pudwell, Systematic Studies in Pattern Avoidance, 2005.
Index entries for linear recurrences with constant coefficients, signature (7,-19,28,-25,13,-3).
FORMULA
G.f.: A(x) = -{(3x^5-9x^4+11x^3-11x^2+5x-1)x}/{(x-1)^3(3x-1)(x^2-x+1)}
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Lara Pudwell, Feb 26 2006
STATUS
approved