A164978 - cp's OEIS frontend

A164978 Number of divisors of n*(n+1)/2 that are >= n.

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

[1, 1, 2, 2, 2, 2, 3, 4, 3, 2, 4, 4, 2, 4, 7, 4, 3, 3, 4, 7, 4, 2, 6, 8, 3, 4, 7, 4, 4, 4, 5, 9, 4, 4, 11, 6, 2, 4, 11, 6, 4, 4, 4, 11, 6, 2, 8, 11, 4, 6, 7, 4, 4, 7, 11, 11, 4, 2, 8, 8, 2, 6, 16, 11, 7, 4, 4, 7, 8, 4, 9, 9, 2, 6, 11, 8, 8, 4, 8, 18, 5, 2, 8, 15, 4, 4, 11, 6, 6, 11, 8, 7, 4, 4, 18, 10, 3, 8]

cp's OEIS Frontend

A164978 Number of divisors of n*(n+1)/2 that are >= n.

Table of values

List of values

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

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

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