A172980 - cp's OEIS frontend

A172980 a(1)=1, a(2)=3; for n>=3, a(n) is the smallest number larger than a(n-1) such that, for every k a(n) is relatively prime to a(k) iff n is relatively prime to k.

n	a(n)
1	1
2	3
3	4
4	9
5	11
6	12
7	13
8	15
9	16
10	33
11	37
12	42
13	43
14	117
15	154
16	159
17	163
18	168
19	173
20	231
21	338
22	555
23	557
24	558
25	649
26	1161
27	1168
28	1209
29	1213
30	1254
31	1259
32	1263
33	1406
34	1467
35	1573
36	1578
37	1579
38	2595
39	2752
40	2805
41	2813
42	2964
43	2969
44	2997
45	3014
46	5013
47	5021
48	5022
49	5057
50	5115

[1, 3, 4, 9, 11, 12, 13, 15, 16, 33, 37, 42, 43, 117, 154, 159, 163, 168, 173, 231, 338, 555, 557, 558, 649, 1161, 1168, 1209, 1213, 1254, 1259, 1263, 1406, 1467, 1573, 1578, 1579, 2595, 2752, 2805, 2813, 2964, 2969, 2997, 3014, 5013, 5021, 5022, 5057, 5115]

cp's OEIS Frontend

A172980 a(1)=1, a(2)=3; for n>=3, a(n) is the smallest number larger than a(n-1) such that, for every k a(n) is relatively prime to a(k) iff n is relatively prime to k.

Table of values

List of values