OFFSET
1,2
COMMENTS
Row sums = A213441.
LINKS
R. C. Read, The number of k-colored graphs on labelled nodes, Canad. J. Math., 12 (1960), 410—414
FORMULA
E.g.f.: Sum_{n>=1} (exp(1 + y)^n*x - 1)*x^n/n!.
EXAMPLE
0,
2, 2,
6, 12, 6,
14, 48, 60, 32, 6,
30, 160, 360, 440, 310, 120, 20,
62, 480, 1680, 3480, 4680, 4212, 2520, 960, 210, 20
MATHEMATICA
nn=10; f[x_]:=Sum[x^n/(n!*(1+y)^(n^2/2)), {n, 0, nn}]; CoefficientList[Table[n!*(1+y)^(n^2/2), {n, 0, nn}]CoefficientList[Series[(f[x]-1)^2, {x, 0, nn}], x]//Simplify//Expand, y]//Grid
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Geoffrey Critzer, Aug 08 2014
STATUS
approved