login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A197872
as a simple table
n
a(n)
1
1
2
4
3
28
4
457
5
19312
6
1569476
7
297589596
8
128297106268
9
121501477787448
[1,4,28,457,19312,1569476,297589596,128297106268, 121501477787448]