A120686 - cp's OEIS frontend

A120686 Integers m such that the sequence defined by f(0)=m and f(n+1)=2+gpf(f(n)), with gpf(n) being the greatest prime factor of n (A006530), ends up in the period 3 cycle 5 -> 7 -> 9 -> 5 -> ...

n	a(n)
0	5
1	10
2	15
3	19
4	20
5	25
6	30
7	31
8	38
9	40
10	45
11	47
12	50
13	53
14	57
15	60
16	61
17	62
18	75
19	76
20	80
21	90
22	93
23	94
24	95
25	97
26	100
27	103
28	106
29	109
30	114
31	120
32	122
33	124
34	125
35	133
36	135
37	141
38	149
39	150
40	152
41	155
42	159
43	160
44	163
45	171
46	173
47	180
48	183
49	186
50	188
51	190
52	191
53	194
54	199
55	200

[5, 10, 15, 19, 20, 25, 30, 31, 38, 40, 45, 47, 50, 53, 57, 60, 61, 62, 75, 76, 80, 90, 93, 94, 95, 97, 100, 103, 106, 109, 114, 120, 122, 124, 125, 133, 135, 141, 149, 150, 152, 155, 159, 160, 163, 171, 173, 180, 183, 186, 188, 190, 191, 194, 199, 200]

cp's OEIS Frontend

A120686 Integers m such that the sequence defined by f(0)=m and f(n+1)=2+gpf(f(n)), with gpf(n) being the greatest prime factor of n (A006530), ends up in the period 3 cycle 5 -> 7 -> 9 -> 5 -> ...

Table of values

List of values

n	a(n)
0	5
1	10
2	15
3	19
4	20
5	25
6	30
7	31
8	38
9	40
10	45
11	47
12	50
13	53
14	57
15	60
16	61
17	62
18	75
19	76
20	80
21	90
22	93
23	94
24	95
25	97
26	100
27	103
28	106
29	109
30	114
31	120
32	122
33	124
34	125
35	133
36	135
37	141
38	149
39	150
40	152
41	155
42	159
43	160
44	163
45	171
46	173
47	180
48	183
49	186
50	188
51	190
52	191
53	194
54	199
55	200

n	a(n)
0	5
1	10
2	15
3	19
4	20
5	25
6	30
7	31
8	38
9	40
10	45
11	47
12	50
13	53
14	57
15	60
16	61
17	62
18	75
19	76
20	80
21	90
22	93
23	94
24	95
25	97
26	100
27	103
28	106
29	109
30	114
31	120
32	122
33	124
34	125
35	133
36	135
37	141
38	149
39	150
40	152
41	155
42	159
43	160
44	163
45	171
46	173
47	180
48	183
49	186
50	188
51	190
52	191
53	194
54	199
55	200

n	a(n)
0	5
1	10
2	15
3	19
4	20
5	25
6	30
7	31
8	38
9	40
10	45
11	47
12	50
13	53
14	57
15	60
16	61
17	62
18	75
19	76
20	80
21	90
22	93
23	94
24	95
25	97
26	100
27	103
28	106
29	109
30	114
31	120
32	122
33	124
34	125
35	133
36	135
37	141
38	149
39	150
40	152
41	155
42	159
43	160
44	163
45	171
46	173
47	180
48	183
49	186
50	188
51	190
52	191
53	194
54	199
55	200