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

Author

N. J. A. Sloane

Keywords

• nonn
• tabf
• easy

Examples

			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;
		

Links

• 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