OFFSET
1,2
COMMENTS
Nonseparable graphs are also called blocks.
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..50
F. Harary and R. W. Robinson, Labeled bipartite blocks, Canad. J. Math., 31 (1979), 60-68.
F. Harary and R. W. Robinson, Labeled bipartite blocks, Canad. J. Math., 31 (1979), 60-68. (Annotated scanned copy)
FORMULA
a(n) = binomial(2*n, n) * A005334(n) / 2. - Andrew Howroyd, Jan 03 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Name clarified and more terms added by Andrew Howroyd, Jan 03 2021
STATUS
approved