login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A007688
as a simple table
n
a(n)
1
4
2
16
3
52
4
144
5
420
6
816
7
1732
8
3508
9
7060
10
18640
[4,16,52,144,420,816,1732,3508,7060,18640]