

A130132


Number of trees on n vertices which are not lobsters.


5



0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 4, 19, 77, 287, 1002, 3365, 10853, 34088, 104574, 315116, 935321, 2743374, 7966723, 22951010, 65681536, 186961873, 529845497, 1496245171, 4213181063, 11836671278, 33195092417, 92966480736
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,11


COMMENTS

Also the number of nonlinear trees on n nodes.  Andrew Howroyd, Dec 17 2020


LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..200
Tanay Wakhare, Eric Wityk, and Charles R. Johnson, The proportion of trees that are linear, Discrete Mathematics, 343.10 (2020): 112008. Also on arXiv, arXiv:1901.08502 [math.CO], 20192020. See Tables 1 and 2 (but beware errors).
Eric Weisstein's World of Mathematics, Lobster Graph


FORMULA

a(n) = A000055(n)  A130131(n).  Andrew Howroyd, Nov 02 2017


CROSSREFS

Cf. A000055, A130131, A331693.
Sequence in context: A167478 A094734 A094578 * A037590 A037681 A156760
Adjacent sequences: A130129 A130130 A130131 * A130133 A130134 A130135


KEYWORD

nonn


AUTHOR

Eric W. Weisstein, May 11 2007


EXTENSIONS

a(15)a(32) from Washington Bomfim, Feb 23 2011


STATUS

approved



