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A036609 Number of 4-ary rooted trees with n nodes and height at most 4. 0
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, 120910, 146797, 175601, 207443, 241515, 277666, 314674, 352152, 388503 (list; graph; refs; listen; history; internal format)
OFFSET

0,4

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

CROSSREFS

Sequence in context: A164148 A065492 A006777 * A027557 A120545 A130708

Adjacent sequences:  A036606 A036607 A036608 * A036610 A036611 A036612

KEYWORD

nonn,fini

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

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Last modified February 17 00:09 EST 2012. Contains 205978 sequences.