A120685 - cp's OEIS frontend

A120685 Integers m such that the sequence defined by f(0)=m and f(n+1)=1+gpf(f(n)), with gpf(n) being the greatest prime factor of n (A006530), ends up in the repetitive cycle 4 -> 3 -> 4 -> ...

n	a(n)
0	2
1	4
2	5
3	8
4	10
5	11
6	13
7	15
8	16
9	17
10	20
11	22
12	23
13	25
14	26
15	30
16	32
17	33
18	34
19	37
20	39
21	40
22	41
23	44
24	45
25	46
26	47
27	50
28	51
29	52
30	53
31	55
32	60
33	61
34	64
35	65
36	66
37	68
38	69
39	71
40	74
41	75
42	77
43	78
44	80
45	82
46	83
47	85
48	88
49	90
50	91
51	92
52	94
53	97
54	99
55	100
56	102
57	104
58	106
59	107
60	110
61	111
62	113
63	115
64	117
65	119
66	120

[2, 4, 5, 8, 10, 11, 13, 15, 16, 17, 20, 22, 23, 25, 26, 30, 32, 33, 34, 37, 39, 40, 41, 44, 45, 46, 47, 50, 51, 52, 53, 55, 60, 61, 64, 65, 66, 68, 69, 71, 74, 75, 77, 78, 80, 82, 83, 85, 88, 90, 91, 92, 94, 97, 99, 100, 102, 104, 106, 107, 110, 111, 113, 115, 117, 119, 120]

cp's OEIS Frontend

A120685 Integers m such that the sequence defined by f(0)=m and f(n+1)=1+gpf(f(n)), with gpf(n) being the greatest prime factor of n (A006530), ends up in the repetitive cycle 4 -> 3 -> 4 -> ...

Table of values

List of values

n	a(n)
0	2
1	4
2	5
3	8
4	10
5	11
6	13
7	15
8	16
9	17
10	20
11	22
12	23
13	25
14	26
15	30
16	32
17	33
18	34
19	37
20	39
21	40
22	41
23	44
24	45
25	46
26	47
27	50
28	51
29	52
30	53
31	55
32	60
33	61
34	64
35	65
36	66
37	68
38	69
39	71
40	74
41	75
42	77
43	78
44	80
45	82
46	83
47	85
48	88
49	90
50	91
51	92
52	94
53	97
54	99
55	100
56	102
57	104
58	106
59	107
60	110
61	111
62	113
63	115
64	117
65	119
66	120

n	a(n)
0	2
1	4
2	5
3	8
4	10
5	11
6	13
7	15
8	16
9	17
10	20
11	22
12	23
13	25
14	26
15	30
16	32
17	33
18	34
19	37
20	39
21	40
22	41
23	44
24	45
25	46
26	47
27	50
28	51
29	52
30	53
31	55
32	60
33	61
34	64
35	65
36	66
37	68
38	69
39	71
40	74
41	75
42	77
43	78
44	80
45	82
46	83
47	85
48	88
49	90
50	91
51	92
52	94
53	97
54	99
55	100
56	102
57	104
58	106
59	107
60	110
61	111
62	113
63	115
64	117
65	119
66	120

n	a(n)
0	2
1	4
2	5
3	8
4	10
5	11
6	13
7	15
8	16
9	17
10	20
11	22
12	23
13	25
14	26
15	30
16	32
17	33
18	34
19	37
20	39
21	40
22	41
23	44
24	45
25	46
26	47
27	50
28	51
29	52
30	53
31	55
32	60
33	61
34	64
35	65
36	66
37	68
38	69
39	71
40	74
41	75
42	77
43	78
44	80
45	82
46	83
47	85
48	88
49	90
50	91
51	92
52	94
53	97
54	99
55	100
56	102
57	104
58	106
59	107
60	110
61	111
62	113
63	115
64	117
65	119
66	120