A003612 Symmetries in unrooted 3-trees on n+1 vertices. (Formerly M0371)

1, 2, 2, 8, 4, 14, 21, 35, 49, 158, 191, 425, 828, 1864, 3659, 8324, 17344, 39601, 87407, 199984, 453361, 1053816, 2426228, 5672389, 13270695, 31277150, 73874375, 175419550, 417535487, 997758788, 2390172398, 5743235470, 13832781125

Offset

1,2

References

Kathleen A. McKeon, The expected number of symmetries in locally-restricted trees I, pp. 849-860 of Y. Alavi et al., eds., Graph Theory, Combinatorics and Applications. Wiley, NY, 2 vols., 1991.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=1..33.

Kathleen A. McKeon, Letter to N. J. A. Sloane, July 25 1991

Kathleen A. McKeon, The expected number of symmetries in locally-restricted trees I, pp. 849-860 of Y. Alavi et al., eds., Graph Theory, Combinatorics and Applications. Wiley, NY, 2 vols., 1991. [Annotated scanned copy]

Index entries for sequences related to trees

Crossrefs

Sequence in context: A134812 A144847 A143625 * A337944 A103839 A135727

Adjacent sequences: A003609 A003610 A003611 * A003613 A003614 A003615

Keyword

nonn

Author

N. J. A. Sloane, Mira Bernstein

Status

approved