login
The OEIS is supported by
the many generous donors to the OEIS Foundation
.
Hints
(Greetings from
The On-Line Encyclopedia of Integer Sequences
!)
A003872
as a simple table
n
a(n)
1
1
2
1
3
7
4
7
5
14
6
14
7
20
8
20
9
21
10
21
11
28
12
28
13
35
14
35
15
42
16
56
17
56
18
64
19
64
20
70
21
70
22
90
[1,1,7,7,14,14,20,20,21,21,28,28,35,35,42,56,56, 64,64,70,70,90]