A106363 - OEIS

A106363

Planar trees where no branch is identical to its adjacent neighbor.

1, 1, 0, 1, 0, 1, 3, 7, 14, 43, 115, 326, 931, 2719, 7979, 23804, 71418, 216444, 660276, 2028558, 6268350, 19479746, 60835542, 190881085, 601459251, 1902680249, 6040955223, 19245061851, 61503863732, 197135868680, 633615135842

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,7

LINKS

Table of n, a(n) for n=1..31.

Index entries for sequences related to trees

FORMULA

G.f.: A(x) = B(x) + (C(x^2) - C(x)^2)/2. B(x) is g.f. of A106362. C(x) is g.f. of A106361.

CROSSREFS

Cf. A002995.

Sequence in context: A298913 A266019 A146155 * A128658 A234042 A001203

Adjacent sequences: A106360 A106361 A106362 * A106364 A106365 A106366

KEYWORD

nonn

AUTHOR

Christian G. Bower, Apr 29 2005

STATUS

approved