A058988 - cp's OEIS frontend

A058988 For a rational number p/q let f(p/q) = p*q divided by number of divisors of p+q; a(n) is obtained by iterating f, starting at n/1, until an integer is reached, or if no integer is ever reached then a(n) = 0.

n	a(n)
1	1
2	1
3	1
4	2
5	30
6	3
7	14
8	12
9	18
10	5
11	33
12	6
13	26
14	21
15	3
16	8
17	51
18	9
19	38
20	5
21	28
22	11
23	92
24	8
25	50
26	0
27	9
28	14
29	116
30	15
31	93
32	8
33	66
34	17
35	105
36	18
37	74
38	0
39	156
40	20
41	492
42	21
43	86
44	22
45	60
46	23
47	0
48	16
49	147
50	0
51	17
52	26
53	212
54	27
55	330
56	14
57	114
58	29
59	354
60	30
61	61
62	186
63	9
64	16
65	260
66	33
67	201
68	17
69	138
70	35
71	426

[1, 1, 1, 2, 30, 3, 14, 12, 18, 5, 33, 6, 26, 21, 3, 8, 51, 9, 38, 5, 28, 11, 92, 8, 50, 0, 9, 14, 116, 15, 93, 8, 66, 17, 105, 18, 74, 0, 156, 20, 492, 21, 86, 22, 60, 23, 0, 16, 147, 0, 17, 26, 212, 27, 330, 14, 114, 29, 354, 30, 61, 186, 9, 16, 260, 33, 201, 17, 138, 35, 426]

cp's OEIS Frontend

A058988 For a rational number p/q let f(p/q) = p*q divided by number of divisors of p+q; a(n) is obtained by iterating f, starting at n/1, until an integer is reached, or if no integer is ever reached then a(n) = 0.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	2
5	30
6	3
7	14
8	12
9	18
10	5
11	33
12	6
13	26
14	21
15	3
16	8
17	51
18	9
19	38
20	5
21	28
22	11
23	92
24	8
25	50
26	0
27	9
28	14
29	116
30	15
31	93
32	8
33	66
34	17
35	105
36	18
37	74
38	0
39	156
40	20
41	492
42	21
43	86
44	22
45	60
46	23
47	0
48	16
49	147
50	0
51	17
52	26
53	212
54	27
55	330
56	14
57	114
58	29
59	354
60	30
61	61
62	186
63	9
64	16
65	260
66	33
67	201
68	17
69	138
70	35
71	426

n	a(n)
1	1
2	1
3	1
4	2
5	30
6	3
7	14
8	12
9	18
10	5
11	33
12	6
13	26
14	21
15	3
16	8
17	51
18	9
19	38
20	5
21	28
22	11
23	92
24	8
25	50
26	0
27	9
28	14
29	116
30	15
31	93
32	8
33	66
34	17
35	105
36	18
37	74
38	0
39	156
40	20
41	492
42	21
43	86
44	22
45	60
46	23
47	0
48	16
49	147
50	0
51	17
52	26
53	212
54	27
55	330
56	14
57	114
58	29
59	354
60	30
61	61
62	186
63	9
64	16
65	260
66	33
67	201
68	17
69	138
70	35
71	426

n	a(n)
1	1
2	1
3	1
4	2
5	30
6	3
7	14
8	12
9	18
10	5
11	33
12	6
13	26
14	21
15	3
16	8
17	51
18	9
19	38
20	5
21	28
22	11
23	92
24	8
25	50
26	0
27	9
28	14
29	116
30	15
31	93
32	8
33	66
34	17
35	105
36	18
37	74
38	0
39	156
40	20
41	492
42	21
43	86
44	22
45	60
46	23
47	0
48	16
49	147
50	0
51	17
52	26
53	212
54	27
55	330
56	14
57	114
58	29
59	354
60	30
61	61
62	186
63	9
64	16
65	260
66	33
67	201
68	17
69	138
70	35
71	426