A014270 Number of trees on n nodes with forbidden limbs.

0, 1, 1, 1, 2, 3, 6, 10, 21, 45, 100, 223, 522, 1234, 2997, 7344, 18325, 46098, 117340, 300935, 778249, 2025542, 5305684, 13972364, 36985033, 98344160, 262612283, 703971120, 1893895747, 5112056798, 13841346542, 37584596256, 102331837104, 279322502700, 764238954757, 2095651789775, 5758646716947, 15855576055018, 43737831483597

Offset

0,5

Links

Table of n, a(n) for n=0..38.

T. Lu, The enumeration of trees with and without given limbs, Discr. Math., 154 (1996), 153-165, Example 3.

Index entries for sequences related to trees

Formula

G.f. x^9+x^11 +g014267(x) -( g014267(x)^2 -g014267(x^2) )/2, where g014267 is the generating function of A014267. - R. J. Mathar, Feb 26 2016

Crossrefs

Sequence in context: A240513 A036650 A049889 * A127076 A137208 A049527

Adjacent sequences: A014267 A014268 A014269 * A014271 A014272 A014273

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved