A109491 - cp's OEIS frontend

A109491 Value of Product_{k=1..n} sigma(k)/sd(k,2), where sd(k,b) is the sum of the digits of k represented in base b.

n	a(n)
1	1
2	3
3	6
4	42
5	126
6	756
7	2016
8	30240
9	196560
10	1769040
11	7076160
12	99066240
13	462309120
14	3698472960
15	22190837760
16	687915970560
17	6191243735040
18	120729252833280
19	804861685555200
20	16902095396659200
21	180289017564364800

[1, 3, 6, 42, 126, 756, 2016, 30240, 196560, 1769040, 7076160, 99066240, 462309120, 3698472960, 22190837760, 687915970560, 6191243735040, 120729252833280, 804861685555200, 16902095396659200, 180289017564364800]

cp's OEIS Frontend

A109491 Value of Product_{k=1..n} sigma(k)/sd(k,2), where sd(k,b) is the sum of the digits of k represented in base b.

Table of values

List of values