OFFSET
0,3
LINKS
S. Heubach and T. Mansour, Enumeration of 3-letter patterns in compositions, arXiv:math/0603285 [math.CO], 2006.
FORMULA
G.f.: 1/(1-Sum(x^j*Product(1-x^(2*i),i=j+1..inf),j=1..inf)).
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Oct 03 2007
STATUS
approved