OFFSET
0,3
COMMENTS
The first difference between this sequence and A000664 is for n=9 edges where we see K_{3,3}, the "utility graph".
FORMULA
Euler transform of A046091.
MATHEMATICA
etr[f_] := Module[{b}, b[n_] := b[n] = If[n == 0, 1, Sum[Sum[d f[d], {d, Divisors[j]}] b[n - j], {j, 1, n}]/n]; b];
a = etr[A046091[[# + 1]]&];
a /@ Range[0, Length[A046091]-1] (* Jean-François Alcover, Jan 01 2022 *)
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Andrew Howroyd, May 05 2021
STATUS
approved