login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A209393
as a simple table
n
a(n)
1
3
2
152
3
22416
4
4488765
5
816320455
[3,152,22416,4488765,816320455]