A286011 - cp's OEIS frontend

A286011 a(1)=1, and for n>1, a(n) is the maximum number of iterations of sigma resulting in n, starting at some integer k; or 0 if n cannot be reached from any k.

n	a(n)
1	1
2	0
3	1
4	2
5	0
6	1
7	3
8	4
9	0
10	0
11	0
12	2
13	1
14	2
15	5
16	0
17	0
18	1
19	0
20	1
21	0
22	0
23	0
24	6
25	0
26	0
27	0
28	3
29	0
30	1
31	1
32	2
33	0
34	0
35	0
36	1
37	0
38	1
39	2
40	1
41	0
42	2
43	0
44	1
45	0
46	0
47	0
48	1
49	0
50	0
51	0
52	0
53	0
54	1
55	0
56	4
57	1
58	0
59	0
60	7
61	0
62	1
63	3
64	0
65	0
66	0
67	0
68	1
69	0
70	0
71	0
72	2
73	0
74	1
75	0
76	0
77	0
78	1
79	0
80	2
81	0
82	0
83	0
84	2
85	0
86	0
87	0
88	0
89	0
90	2

[1, 0, 1, 2, 0, 1, 3, 4, 0, 0, 0, 2, 1, 2, 5, 0, 0, 1, 0, 1, 0, 0, 0, 6, 0, 0, 0, 3, 0, 1, 1, 2, 0, 0, 0, 1, 0, 1, 2, 1, 0, 2, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 4, 1, 0, 0, 7, 0, 1, 3, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 1, 0, 0, 0, 1, 0, 2, 0, 0, 0, 2, 0, 0, 0, 0, 0, 2]

cp's OEIS Frontend

A286011 a(1)=1, and for n>1, a(n) is the maximum number of iterations of sigma resulting in n, starting at some integer k; or 0 if n cannot be reached from any k.

Table of values

List of values

n	a(n)
1	1
2	0
3	1
4	2
5	0
6	1
7	3
8	4
9	0
10	0
11	0
12	2
13	1
14	2
15	5
16	0
17	0
18	1
19	0
20	1
21	0
22	0
23	0
24	6
25	0
26	0
27	0
28	3
29	0
30	1
31	1
32	2
33	0
34	0
35	0
36	1
37	0
38	1
39	2
40	1
41	0
42	2
43	0
44	1
45	0
46	0
47	0
48	1
49	0
50	0
51	0
52	0
53	0
54	1
55	0
56	4
57	1
58	0
59	0
60	7
61	0
62	1
63	3
64	0
65	0
66	0
67	0
68	1
69	0
70	0
71	0
72	2
73	0
74	1
75	0
76	0
77	0
78	1
79	0
80	2
81	0
82	0
83	0
84	2
85	0
86	0
87	0
88	0
89	0
90	2

n	a(n)
1	1
2	0
3	1
4	2
5	0
6	1
7	3
8	4
9	0
10	0
11	0
12	2
13	1
14	2
15	5
16	0
17	0
18	1
19	0
20	1
21	0
22	0
23	0
24	6
25	0
26	0
27	0
28	3
29	0
30	1
31	1
32	2
33	0
34	0
35	0
36	1
37	0
38	1
39	2
40	1
41	0
42	2
43	0
44	1
45	0
46	0
47	0
48	1
49	0
50	0
51	0
52	0
53	0
54	1
55	0
56	4
57	1
58	0
59	0
60	7
61	0
62	1
63	3
64	0
65	0
66	0
67	0
68	1
69	0
70	0
71	0
72	2
73	0
74	1
75	0
76	0
77	0
78	1
79	0
80	2
81	0
82	0
83	0
84	2
85	0
86	0
87	0
88	0
89	0
90	2

n	a(n)
1	1
2	0
3	1
4	2
5	0
6	1
7	3
8	4
9	0
10	0
11	0
12	2
13	1
14	2
15	5
16	0
17	0
18	1
19	0
20	1
21	0
22	0
23	0
24	6
25	0
26	0
27	0
28	3
29	0
30	1
31	1
32	2
33	0
34	0
35	0
36	1
37	0
38	1
39	2
40	1
41	0
42	2
43	0
44	1
45	0
46	0
47	0
48	1
49	0
50	0
51	0
52	0
53	0
54	1
55	0
56	4
57	1
58	0
59	0
60	7
61	0
62	1
63	3
64	0
65	0
66	0
67	0
68	1
69	0
70	0
71	0
72	2
73	0
74	1
75	0
76	0
77	0
78	1
79	0
80	2
81	0
82	0
83	0
84	2
85	0
86	0
87	0
88	0
89	0
90	2