A133780 - cp's OEIS frontend

A133780 Irregular array: n-th row lists the "non-isolated divisors" of (2n). A positive divisor, k, of n is non-isolated if (k-1) or (k+1) also divides n.

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

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

cp's OEIS Frontend

A133780 Irregular array: n-th row lists the "non-isolated divisors" of (2n). A positive divisor, k, of n is non-isolated if (k-1) or (k+1) also divides n.

Table of values

List of values

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

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

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