OFFSET
1,2
COMMENTS
Should be straightforward to give a formula in terms of path counts on complete graph K_n.
Sequence extended to n=1 using formula. - Andrew Howroyd, Jun 19 2017
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..50
Eric Weisstein's World of Mathematics, Barbell Graph
Eric Weisstein's World of Mathematics, Graph Path
FORMULA
MATHEMATICA
Table[E (E Gamma[n, 1]^2 + Gamma[n + 1, 1]) - n - 1, {n, 20}]
PROG
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, Jun 13 2017
EXTENSIONS
a(1)-a(2) and a(10)-a(18) from Andrew Howroyd, Jun 19 2017
STATUS
approved