A108640 - cp's OEIS frontend

A108640 a(n) = Product_{k=1..n} sigma_{n-k}(k), where sigma_m(k) = sum{j|k} j^m.

n	a(n)
1	1
2	2
3	6
4	60
5	1260
6	239904
7	123263712
8	872883648000
9	35330106763980000
10	15502816844111220549120
11	32196148399600498119169883520
12	2560463149313858442381787649990400000
13	717635502576022020068175045395317927056000000

[1, 2, 6, 60, 1260, 239904, 123263712, 872883648000, 35330106763980000, 15502816844111220549120, 32196148399600498119169883520, 2560463149313858442381787649990400000, 717635502576022020068175045395317927056000000]

cp's OEIS Frontend

A108640 a(n) = Product_{k=1..n} sigma_{n-k}(k), where sigma_m(k) = sum{j|k} j^m.

Table of values

List of values