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A055291 Number of trees with n nodes and 4 leaves. 1
1, 2, 4, 8, 14, 23, 36, 54, 78, 110, 150, 201, 264, 341, 433, 544, 674, 827, 1004, 1209, 1443, 1711, 2013, 2355, 2738, 3167, 3643, 4173, 4757, 5402, 6109, 6885, 7731, 8655, 9657, 10746, 11923, 13196, 14566, 16043, 17627, 19328, 21147, 23094 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,2

LINKS

Table of n, a(n) for n=5..48.

Index entries for sequences related to trees

FORMULA

G.f.: x^5(x^5+x^3+1)/[(1-x^3)(1+x^2)(1-x^2)^2(1-x)^2].

CROSSREFS

Column 4 of A055290.

Sequence in context: A138526 A201347 A089054 * A091773 A107055 A202840

Adjacent sequences:  A055288 A055289 A055290 * A055292 A055293 A055294

KEYWORD

nonn

AUTHOR

Christian G. Bower, May 09 2000

STATUS

approved

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Last modified December 11 03:18 EST 2016. Contains 279034 sequences.