A153024 - cp's OEIS frontend

A153024 a(n) is the number of iterations of the map k -> A048050(k) to reach zero. If we never reach 0, then a(n) = -1. A048050 gives the sum of proper divisors of k, excluding both 1 and n from the sum.

n	a(n)
1	1
2	1
3	1
4	2
5	1
6	2
7	1
8	3
9	2
10	2
11	1
12	5
13	1
14	3
15	4
16	4
17	1
18	5
19	1
20	4
21	3
22	2
23	1
24	7
25	2
26	5
27	6
28	7
29	1
30	2
31	1
32	3
33	4
34	2
35	6
36	8
37	1
38	4
39	5
40	3
41	1
42	2
43	1
44	6
45	4
46	3
47	1
48	-1
49	2
50	3
51	5
52	5
53	1
54	7
55	5
56	5
57	3
58	2
59	1
60	2
61	1
62	5
63	4
64	6
65	6
66	7
67	1
68	4
69	6
70	2
71	1
72	6
73	1
74	6
75	-1
76	5
77	6
78	2
79	1
80	7
81	6
82	2
83	1
84	2
85	3
86	5
87	4
88	6
89	1
90	9
91	5
92	-1
93	3
94	3
95	8
96	10
97	1
98	7
99	6
100	5
101	1
102	2
103	1
104	7
105	6

[1, 1, 1, 2, 1, 2, 1, 3, 2, 2, 1, 5, 1, 3, 4, 4, 1, 5, 1, 4, 3, 2, 1, 7, 2, 5, 6, 7, 1, 2, 1, 3, 4, 2, 6, 8, 1, 4, 5, 3, 1, 2, 1, 6, 4, 3, 1, -1, 2, 3, 5, 5, 1, 7, 5, 5, 3, 2, 1, 2, 1, 5, 4, 6, 6, 7, 1, 4, 6, 2, 1, 6, 1, 6, -1, 5, 6, 2, 1, 7, 6, 2, 1, 2, 3, 5, 4, 6, 1, 9, 5, -1, 3, 3, 8, 10, 1, 7, 6, 5, 1, 2, 1, 7, 6]

cp's OEIS Frontend

A153024 a(n) is the number of iterations of the map k -> A048050(k) to reach zero. If we never reach 0, then a(n) = -1. A048050 gives the sum of proper divisors of k, excluding both 1 and n from the sum.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	2
5	1
6	2
7	1
8	3
9	2
10	2
11	1
12	5
13	1
14	3
15	4
16	4
17	1
18	5
19	1
20	4
21	3
22	2
23	1
24	7
25	2
26	5
27	6
28	7
29	1
30	2
31	1
32	3
33	4
34	2
35	6
36	8
37	1
38	4
39	5
40	3
41	1
42	2
43	1
44	6
45	4
46	3
47	1
48	-1
49	2
50	3
51	5
52	5
53	1
54	7
55	5
56	5
57	3
58	2
59	1
60	2
61	1
62	5
63	4
64	6
65	6
66	7
67	1
68	4
69	6
70	2
71	1
72	6
73	1
74	6
75	-1
76	5
77	6
78	2
79	1
80	7
81	6
82	2
83	1
84	2
85	3
86	5
87	4
88	6
89	1
90	9
91	5
92	-1
93	3
94	3
95	8
96	10
97	1
98	7
99	6
100	5
101	1
102	2
103	1
104	7
105	6

n	a(n)
1	1
2	1
3	1
4	2
5	1
6	2
7	1
8	3
9	2
10	2
11	1
12	5
13	1
14	3
15	4
16	4
17	1
18	5
19	1
20	4
21	3
22	2
23	1
24	7
25	2
26	5
27	6
28	7
29	1
30	2
31	1
32	3
33	4
34	2
35	6
36	8
37	1
38	4
39	5
40	3
41	1
42	2
43	1
44	6
45	4
46	3
47	1
48	-1
49	2
50	3
51	5
52	5
53	1
54	7
55	5
56	5
57	3
58	2
59	1
60	2
61	1
62	5
63	4
64	6
65	6
66	7
67	1
68	4
69	6
70	2
71	1
72	6
73	1
74	6
75	-1
76	5
77	6
78	2
79	1
80	7
81	6
82	2
83	1
84	2
85	3
86	5
87	4
88	6
89	1
90	9
91	5
92	-1
93	3
94	3
95	8
96	10
97	1
98	7
99	6
100	5
101	1
102	2
103	1
104	7
105	6

n	a(n)
1	1
2	1
3	1
4	2
5	1
6	2
7	1
8	3
9	2
10	2
11	1
12	5
13	1
14	3
15	4
16	4
17	1
18	5
19	1
20	4
21	3
22	2
23	1
24	7
25	2
26	5
27	6
28	7
29	1
30	2
31	1
32	3
33	4
34	2
35	6
36	8
37	1
38	4
39	5
40	3
41	1
42	2
43	1
44	6
45	4
46	3
47	1
48	-1
49	2
50	3
51	5
52	5
53	1
54	7
55	5
56	5
57	3
58	2
59	1
60	2
61	1
62	5
63	4
64	6
65	6
66	7
67	1
68	4
69	6
70	2
71	1
72	6
73	1
74	6
75	-1
76	5
77	6
78	2
79	1
80	7
81	6
82	2
83	1
84	2
85	3
86	5
87	4
88	6
89	1
90	9
91	5
92	-1
93	3
94	3
95	8
96	10
97	1
98	7
99	6
100	5
101	1
102	2
103	1
104	7
105	6