OFFSET
0,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..50
Edward A. Bender and E. Rodney Canfield, Enumeration of connected invariant graphs, Journal of Combinatorial Theory, Series B 34.3 (1983): 268-278. See p. 274.
N. J. A. Sloane, Transforms
FORMULA
EULERi transform of A004103.
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 25 2018
EXTENSIONS
a(0)=1 prepended by Andrew Howroyd, Jan 26 2020
STATUS
approved