OFFSET
1,2
COMMENTS
Perfect matchings exist only for graphs with an even number of nodes.
LINKS
Eric Weisstein's World of Mathematics, Connected Graph
Eric Weisstein's World of Mathematics, Perfect Matching
FORMULA
Inverse Euler transform of A218462. - Andrew Howroyd, Nov 03 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Eric W. Weisstein, Mar 26 2013
STATUS
approved