

A193129


Number of spanning trees of the nbarbell graph.


1



1, 1, 1, 9, 256, 15625, 1679616, 282475249, 68719476736, 22876792454961, 10000000000000000, 5559917313492231481, 3833759992447475122176, 3211838877954855105157369, 3214199700417740936751087616, 3787675244106352329254150390625
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OFFSET

0,4


COMMENTS

a(n) = A000272(n)^2 for n>=0.


LINKS

M. F. Hasler, Table of n, a(n) for n = 3..32 (Terms given in the DATA section of an earlier version.) Eric Weisstein's World of Mathematics, Barbell Graph
Eric Weisstein's World of Mathematics, Spanning Tree


FORMULA

a(0)=1 and a(n)=n^(2n4) for n>=1 (from the comment and the formula for A000272).


MATHEMATICA

Table[n^(2 n  4), {n, 3, 20}]


PROG

(PARI) A193129=n^(2*n4) \\ M. F. Hasler, Apr 14 2015


CROSSREFS

Cf. A000272.
Sequence in context: A212290 A296950 A025133 * A183493 A183424 A160073
Adjacent sequences: A193126 A193127 A193128 * A193130 A193131 A193132


KEYWORD

nonn


AUTHOR

Eric W. Weisstein, Jul 16 2011


STATUS

approved



