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A193130 Numbers of spanning trees of the cocktail party graphs. 1
0, 4, 384, 82944, 32768000, 20736000000, 19271206305792, 24759631762948096, 42071440246337175552, 91403961001574400000000, 247248735803801600000000000, 815050629127324260701847945216, 3217014140995401936351315753959424, 14980394406548644878469798644485718016, 81273091789297371841938063360000000000000, 508205981119602242207392727040000000000000000, 3628552299353537995762377908883806653710407303168, 29340027666972879901888631956084208569950431719981056, 266728029815473275232435732938925201095349516481203273728, 2708643047300332999377293213900260859969536000000000000000000 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

A closed form appears to be given by n^(n-2) * (n-1)^n * 4^(n-1). - Felix A. Pahl, May 06 2013

Number of trees on 2n labeled vertices containing no edges from a prescribed perfect matching. - Joel B. Lewis, Jun 20 2013

LINKS

Table of n, a(n) for n=1..20.

Eric Weisstein's World of Mathematics, Cocktail Party Graph

Eric Weisstein's World of Mathematics, Spanning Tree

CROSSREFS

Sequence in context: A154569 A038015 A003753 * A006237 A181044 A116031

Adjacent sequences:  A193127 A193128 A193129 * A193131 A193132 A193133

KEYWORD

nonn

AUTHOR

Eric W. Weisstein, Jul 16 2011

STATUS

approved

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Last modified November 27 23:10 EST 2014. Contains 250286 sequences.