login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A123787
as a simple table
n
a(n)
1
1
2
2
3
28
4
192
5
1680
6
13644
7
118916
8
1044873
9
9160772
[1,2,28,192,1680,13644,118916,1044873,9160772]