OFFSET
4,1
LINKS
S. Kitaev, J. Remmel and M. Tiefenbruck, Marked mesh patterns in 132-avoiding permutations I, arXiv preprint arXiv:1201.6243, 2012
MATHEMATICA
QQ0[t, x] = (1 - (1-4*x*t)^(1/2)) ) / (2*x*t); QQ1[t, x] = 1/(1 - t*QQ0[t, x]); QQ2[t, x] = (1 + t*(QQ1[t, x] - QQ0[t, x]))/(1 - t*QQ0[t, x]); QQ3[t, x] = (1 + t*(QQ2[t, x] - QQ0[t, x] + t*(QQ1[t, x] - QQ0[t, x])))/(1 - t*QQ0[t, x]); Simplify[Series[QQ3[t, x], {t, 0, 35}]] (* Robert Price, Jun 03 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, May 09 2012
EXTENSIONS
a(9) corrected by Robert Price, Jun 03 2012
a(10)-a(35) from Robert Price, Jun 03 2012
STATUS
approved