A007117 - cp's OEIS frontend

A007117 a(0) = a(1) = 0; for n >= 2, a(n)*2^(n+2) + 1 is the smallest prime factor of the n-th Fermat number F(n) = 2^(2^n) + 1.

n	a(n)
0	0
1	0
2	1
3	8
4	1024
5	5
6	1071
7	116503103764643
8	1209889024954
9	1184
10	11131
11	39
12	7
13	82731770
14	1784180997819127957596374417642156545110881094717
15	9264
16	3150
17	59251857
18	13
19	33629

[0, 0, 1, 8, 1024, 5, 1071, 116503103764643, 1209889024954, 1184, 11131, 39, 7, 82731770, 1784180997819127957596374417642156545110881094717, 9264, 3150, 59251857, 13, 33629]

cp's OEIS Frontend

A007117 a(0) = a(1) = 0; for n >= 2, a(n)*2^(n+2) + 1 is the smallest prime factor of the n-th Fermat number F(n) = 2^(2^n) + 1.

Table of values

List of values