A014281 Number of trees on n nodes with forbidden limbs.

0, 1, 1, 1, 1, 2, 3, 4, 9, 18, 40, 84, 189, 425, 986, 2298, 5465, 13072, 31661, 77173, 189697, 468969, 1166720, 2916983, 7329321, 18494428, 46859177, 119161865, 304076055, 778399130, 1998552928, 5145515877, 13282204144, 34368982552, 89136810772

Offset

0,6

Links

Table of n, a(n) for n=0..34.

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

Index entries for sequences related to trees

Formula

G.f. x^5+x^6 +g014280(x) -(g014280(x)^2 - g014280(x^2) )/2, where g015280 is the o.g.f. of A014280. - R. J. Mathar, Feb 27 2016

Crossrefs

Sequence in context: A088275 A274836 A322783 * A220364 A243902 A086865

Adjacent sequences: A014278 A014279 A014280 * A014282 A014283 A014284

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved