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Symmetries in unrooted (1,3) trees on 2n vertices.
(Formerly M1565)
0

%I M1565 #17 Feb 24 2019 16:06:05

%S 2,6,8,8,56,24,168,240,608,920,5680,6104,18416,43008,148152,325608,

%T 980840,2421096,7336488,19769312,58192608,164776248,502085760,

%U 1427051544,4261678656,12615722288,37914214232,113567513528,343641240328,1039134670952

%N Symmetries in unrooted (1,3) trees on 2n vertices.

%D 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.

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

%H Kathleen A. McKeon, <a href="/A003609/a003609.pdf">Letter to N. J. A. Sloane, July 25 1991</a>

%H Kathleen A. McKeon, <a href="/A003609/a003609_1.pdf">The expected number of symmetries in locally-restricted trees I</a>, pp. 849-860 of Y. Alavi et al., eds., Graph Theory, Combinatorics and Applications. Wiley, NY, 2 vols., 1991. [Annotated scanned copy]

%H <a href="/index/Tra#trees">Index entries for sequences related to trees</a>

%K nonn

%O 1,1

%A _N. J. A. Sloane_, _Mira Bernstein_

%E More terms from _Sean A. Irvine_, Feb 24 2019