login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A134983
as a simple table
n
a(n)
1
1
2
2
3
4
4
12
5
40
6
168
7
784
8
4272
9
25504
10
171168
11
1242688
12
9915072
13
84714112
14
783454848
15
7697178880
[1,2,4,12,40,168,784,4272,25504,171168,1242688, 9915072,84714112,783454848,7697178880]