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Number of n-node labeled bipartite graphs without isolated nodes.
1

%I #14 May 10 2013 12:45:46

%S 1,0,1,3,22,225,3421,73668,2222977,93033615,5393456986,433396737873,

%T 48429436851577,7548123580987080,1646092439020192801,

%U 503469306031901522043,216430661498688457821022,130959358877474026010486145,111687660283090149155082836341

%N Number of n-node labeled bipartite graphs without isolated nodes.

%H Alois P. Heinz, <a href="/A120667/b120667.txt">Table of n, a(n) for n = 0..60</a>

%F E.g.f.: sqrt( e.g.f. for A052332 ) = sqrt(Sum_{n>=0} exp(x*(2^n-2)) * x^n/n!).

%p a:= n-> coeff (series (sqrt (add (exp (x*(2^k-2)) *x^k/k!, k=0..n)), x, n+1), x, n)*n!: seq (a(n), n=0..20); # _Alois P. Heinz_, Sep 12 2008

%Y Cf. A047864.

%K easy,nonn

%O 0,4

%A _Vladeta Jovovic_, Jun 23 2007

%E More terms from _Alois P. Heinz_, Sep 12 2008