A103759 - cp's OEIS frontend

A103759 a(n) = sigma((10^n - 1)/9), where sigma(n) is the sum of positive divisors of n.

n	a(n)
1	1
2	12
3	152
4	1224
5	11424
6	204288
7	1116000
8	12499488
9	164831992
10	1246404096
11	11111646000
12	206331697152
13	1146405545280
14	12174560064000
15	161484774162432
16	1323475438225536
17	11111116476405192
18	232965361825996800

[1, 12, 152, 1224, 11424, 204288, 1116000, 12499488, 164831992, 1246404096, 11111646000, 206331697152, 1146405545280, 12174560064000, 161484774162432, 1323475438225536, 11111116476405192, 232965361825996800]

cp's OEIS Frontend

A103759 a(n) = sigma((10^n - 1)/9), where sigma(n) is the sum of positive divisors of n.

Table of values

List of values