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A342988 Number of tree-rooted planar maps with n edges and no isthmuses. 3
1, 1, 4, 23, 162, 1292, 11214, 103497, 1000810, 10039100, 103725188, 1098151276, 11866435816, 130477138014, 1456320910090, 16468167354971, 188369396046810, 2176619115192140, 25379588118629856, 298341351434460488, 3532848638781046852, 42113699799069958732 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Andrew Howroyd, Table of n, a(n) for n = 0..500

FORMULA

G.f.: A(x) satisfies A(x) = G(x*A(x)^2) where G(x) + x is the g.f. of A004304.

PROG

(PARI) \\ here J(n) gives A004304 as g.f.

J(n)={my(g=(1-sqrt(1-4*x+O(x^3*x^n)))/(2*x), h=serconvol(g, (g-1)/x)); sqrt(x/serreverse(x*h^2))}

seq(n)={my(g=J(n)-x, p=O(1)); while(serprec(p, x)<=n, p = subst(g, x, x*p^2)); Vec(p)}

CROSSREFS

Row sums of A342987.

Cf. A004304, A342986.

Sequence in context: A182969 A263186 A245110 * A304074 A307402 A111547

Adjacent sequences:  A342985 A342986 A342987 * A342989 A342991 A342992

KEYWORD

nonn

AUTHOR

Andrew Howroyd, Apr 03 2021

STATUS

approved

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Last modified January 24 21:35 EST 2022. Contains 350565 sequences. (Running on oeis4.)