OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..80
FORMULA
a(n) = Sum_{i=0..n} binomial(n,i)*A001187(i).
E.g.f.: exp(x)*A(x) where A(x) is e.g.f. for A001187.
a(n) = A327078(n) + n. - Gus Wiseman, Sep 03 2019
EXAMPLE
From Gus Wiseman, Sep 03 2019: (Start)
The a(0) = 1 through a(3) = 11 edge-sets (singletons represent uncovered vertices):
{} {} {} {}
{{1}} {{1}} {{1}}
{{2}} {{2}}
{{1,2}} {{3}}
{{1,2}}
{{1,3}}
{{2,3}}
{{1,2},{1,3}}
{{1,2},{2,3}}
{{1,3},{2,3}}
{{1,2},{1,3},{2,3}}
(End)
MATHEMATICA
nn = 15; g = Sum[2^Binomial[n, 2] x^n/n!, {n, 0, nn}]; Range[0, nn]! CoefficientList[Series[Exp[x] (Log[g] + 1), {x, 0, nn}], x]
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Critzer, Apr 11 2012
STATUS
approved