login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A018566
as a simple table
n
a(n)
1
1
2
2
3
3
4
6
5
107
6
214
7
321
8
642
[1,2,3,6,107,214,321,642]