OFFSET
1,2
COMMENTS
Is this the same as A000081 with a different offset? - N. J. A. Sloane
Yes, because it equals the number of rooted forests with n nodes (see Golumbic reference). The Euler transform shifts this sequence by one. Thus the number of connected trivially-perfect graphs on n nodes is a(n-1). - Falk Hüffner, Nov 26 2015
LINKS
M. C. Golumbic, Trivially perfect graphs, Discr. Math. 24(1) (1978), 105-107.
S. Hougardy, Home Page
S. Hougardy, Classes of perfect graphs, Discr. Math. 306 (2006), 2529-2571.
FORMULA
a(n) = A000081(n+1) - Falk Hüffner, Nov 26 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Oct 18 2006
STATUS
approved