A220900 A restricted class of multiple edge-free maps on n edges.

1, 0, 1, 1, 5, 13, 48, 160, 578, 2078, 7658, 28467, 107096, 406290, 1553570, 5980040, 23154950, 90124865, 352423336, 1383872558, 5454586036, 21572961498, 85587023964, 340518976173, 1358341426234, 5431524909088, 21767112830811, 87412948227174, 351709144912372

Offset

1,5

Comments

See Kitaev et al. for precise definition.

Links

Table of n, a(n) for n=1..29.

S. Kitaev, P. Salimov, C. Severs and H. Ulfarsson, Restricted non-separable planar maps and some pattern avoiding permutations, preprint 2012.

S. Kitaev, P. Salimov, C. Severs and H. Ulfarsson, Restricted non-separable planar maps and some pattern avoiding permutations, Discrete Applied Mathematics, Volume 161, Issues 16-17, November 2013, Pages 2514-2526. See B_3(x).

Formula

Kitaev et al. give a functional equation that is satisfied by the g.f.

Prog

(PARI)
a(n) = {
  B = x + O(x^(n+1));
  for (i=1, n,
      B = x + B*(B-x) + (B-x)^2 + (B-x-x*B^2)*(B-x) + x*(3*B-2*x-x*B^2)^2; );
  polcoeff(B, n, x);
}  \\ Michel Marcus, Feb 07 2013

Crossrefs

Sequence in context: A025545 A146152 A082132 * A138277 A343549 A084601

Adjacent sequences: A220897 A220898 A220899 * A220901 A220902 A220903

Keyword

nonn

Author

N. J. A. Sloane, Jan 01 2013

Extensions

More terms from Michel Marcus, Feb 07 2013

Status

approved