|
|
A091479
|
|
Number of graphs with n nodes. Nodes and edges labeled each from their own label set.
|
|
2
|
|
|
1, 1, 2, 16, 1957, 9864101, 3554627472076, 138879579704209680022, 828772446866981044847857913441, 1011182700521015817607065606491025592595137, 325166909258549255903203528672831330994640286650913570126
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
LINKS
|
|
|
FORMULA
|
|
|
PROG
|
(PARI) a(n)={binomial(n, 2)!*sum(k=0, binomial(n, 2), 1/k!)} \\ Andrew Howroyd, Feb 12 2020
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
a(0)=1 prepended and terms a(10) and beyond from Andrew Howroyd, Feb 12 2020
|
|
STATUS
|
approved
|
|
|
|