OFFSET
0,5
COMMENTS
A bi-point determining graph is a graph in which no two vertices have the same neighborhoods or the same augmented neighborhoods (the augmented neighborhood of a vertex is the neighborhood of the vertex union the vertex itself).
REFERENCES
R. C. Read, The Enumeration of Mating-Type Graphs. Report CORR 89-38, Dept. Combinatorics and Optimization, Univ. Waterloo, 1989.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..50
Ira M. Gessel and Ji Li, Enumeration of point-determining Graphs, Journal of Combinatorial Theory, Series A 118 (2011) 591-612.
FORMULA
E.g.f.: G(2*log(1+x)-x) where G(x) is the e.g.f. of A006125.
PROG
(PARI) seq(n)={my(g=sum(k=0, n, 2^binomial(k, 2)*x^k/k!) + O(x*x^n)); Vec(serlaplace(subst(g, x, 2*log(1+x+O(x*x^n))-x)))} \\ Andrew Howroyd, May 06 2021
CROSSREFS
Cf. graphs: labeled A006125, unlabeled A000568; connected graphs: labeled A001187, unlabeled A001349; point-determining graphs: labeled A006024, unlabeled A004110; connected point-determining graphs: labeled A092430, unlabeled A004108; connected co-point-determining graphs: labeled A079306, unlabeled A004108; bi-point-determining graphs: labeled A129583, unlabeled A129584; connected bi-point-determining graphs: labeled A129585, unlabeled A129586; phylogenetic trees: labeled A000311, unlabeled A000669.
KEYWORD
nice,nonn
AUTHOR
Ji Li (vieplivee(AT)hotmail.com), May 07 2007
EXTENSIONS
a(0)=1 prepended and terms a(13) and beyond from Andrew Howroyd, May 06 2021
STATUS
approved