OFFSET
5,1
LINKS
S. Kitaev, J. Remmel and M. Tiefenbruck, Marked mesh patterns in 132-avoiding permutations I, arXiv preprint arXiv:1201.6243, 2012
FORMULA
Empirical g.f.: -x^5*(25*x^3+20*x^2+14*x+14) / (5*x^4+2*x^3+x^2+x-1)^3. - Colin Barker, Jul 22 2013
MATHEMATICA
QQQ4[t, x] = 2/(1+(t*x-t)*(1+t+2*t^2+5*t^3)+((1+(t*x-t)*(1+t+2*t^2+5*t^3))^2-4*t*x)^(1/2)); CoefficientList[Coefficient[Series[QQQ4[t, x], {t, 0, 22}], x], t] (* Robert Price, Jun 05 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 09 2012
EXTENSIONS
a(10)-a(22) from Robert Price, Jun 04 2012
STATUS
approved