A309981 - cp's OEIS frontend

A309981 a(n) is the smallest number k such that the value of n can be deduced given only the values tau(n), tau(n+1), ..., tau(n+k), where tau is the number of divisors function.

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

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

cp's OEIS Frontend

A309981 a(n) is the smallest number k such that the value of n can be deduced given only the values tau(n), tau(n+1), ..., tau(n+k), where tau is the number of divisors function.

Table of values

List of values

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

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

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