OFFSET
1,2
LINKS
A. R. Rao, Table of n, a(n) for n = 1..200
A. R. Rao, The number of reachable pairs in a digraph, Discr. Math., 306 (2006), 1595-1600.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 27 2006
STATUS
approved