login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A010787
as a simple table
n
a(n)
1
1
2
1
3
2
4
6
5
25
6
135
7
913
8
7499
9
73191
10
833597
11
10917343
12
162402263
[1,1,2,6,25,135,913,7499,73191,833597,10917343, 162402263]