A307119 - cp's OEIS frontend

A307119 a(1) = 1, for n>1, a(n) = dp(n-1) + dp(n) + dp(n+1), where dp(n) is the number of divisors of n less than n (A032741).

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

[1, 2, 4, 4, 6, 5, 7, 6, 8, 6, 9, 7, 9, 7, 10, 8, 10, 7, 11, 9, 11, 7, 11, 10, 12, 8, 11, 9, 13, 9, 13, 9, 11, 9, 14, 12, 12, 7, 13, 11, 15, 9, 13, 11, 13, 9, 13, 12, 16, 10, 13, 9, 13, 11, 17, 13, 13, 7, 15, 13, 15, 9, 14, 14, 16, 11, 13, 9, 15, 11, 19, 13, 15, 9, 13, 13, 15, 11, 17, 14, 16, 8]

cp's OEIS Frontend

A307119 a(1) = 1, for n>1, a(n) = dp(n-1) + dp(n) + dp(n+1), where dp(n) is the number of divisors of n less than n (A032741).

Table of values

List of values

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

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

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