A036606 Triangle of coefficients of generating function of 4-ary rooted trees of height at most n.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 5, 6, 8, 9, 11, 11, 12, 11, 11, 9, 8, 6, 5, 3, 2, 1, 1, 1, 1, 1, 2, 4, 8, 14, 26, 44, 76, 125, 206, 327, 521, 802, 1231, 1845, 2742, 3987, 5748, 8124, 11364, 15615, 21212, 28336, 37412, 48597, 62368, 78810, 98359

Offset

0,13

Links

Table of n, a(n) for n=0..60.

E. M. Rains and N. J. A. Sloane, On Cayley's Enumeration of Alkanes (or 4-Valent Trees), J. Integer Sequences, Vol. 2 (1999), Article 99.1.1.

Index entries for sequences related to rooted trees

Example

Triangle begins:
1;
1,1;
1,1,1,1,1,1;
1,1,1,2,3,5,6,8,9,11,11,12,11,11,9,8,6,5,3,2,1,1;

Crossrefs

Sequence in context: A026194 A289279 A102420 * A051837 A026371 A187335

Adjacent sequences: A036603 A036604 A036605 * A036607 A036608 A036609

Keyword

nonn,tabf,easy

Author

N. J. A. Sloane.

Status

approved