A223889 The number of connected components of size > 1 over all simple labeled graphs on n nodes.

0, 0, 1, 7, 66, 1078, 33812, 2124864, 269617328, 68809824944, 35197776962400, 36032789666289920, 73789365506598519808, 302234307608870314427904, 2475886847109430725963593728, 40564851077856428731075010538496

Offset

0,4

Links

Table of n, a(n) for n=0..15.

Formula

E.g.f.: (A(x) - x - 1)*B(x) where A(x) is the e.g.f. for A001187 and B(x) is the e.g.f. for A006125.

Mathematica

nn=15; g=Sum[2^Binomial[n, 2]x^n/n!, {n, 0, nn}]; Range[0, nn]!CoefficientList[Series[(Log[g]-x)g, {x, 0, nn}], x]

Crossrefs

Cf. A125207

Sequence in context: A215077 A003286 A244602 * A197744 A052351 A210476

Adjacent sequences: A223886 A223887 A223888 * A223890 A223891 A223892

Keyword

nonn

Author

Geoffrey Critzer, Mar 28 2013

Status

approved