OFFSET
0,3
FORMULA
EXAMPLE
a(3) = 456 because there are 432 connected relations on [3]. Then there are 12 connected relations on [2] and for each the element 3 may be related to itself or not.
432 + 2*12 = 456.
MATHEMATICA
nn=10; g=Sum[2^n^2 x^n/n!, {n, 0, nn+2}]; Join[{0, 0}, Range[0, nn]! * CoefficientList[Series[D[D[Log[g], x], x]g , {x, 0, nn}], x]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Critzer, Jun 04 2013
STATUS
approved