A243055 - cp's OEIS frontend

A243055 Difference between the indices of the smallest and the largest prime dividing n: If n = p_i * ... * p_k, where p_i <= ... <= p_k, where p_h = A000040(h), then a(n) = (k-i), a(1) = 0 by convention.

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

[0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 1, 0, 3, 1, 0, 0, 1, 0, 2, 2, 4, 0, 1, 0, 5, 0, 3, 0, 2, 0, 0, 3, 6, 1, 1, 0, 7, 4, 2, 0, 3, 0, 4, 1, 8, 0, 1, 0, 2, 5, 5, 0, 1, 2, 3, 6, 9, 0, 2, 0, 10, 2, 0, 3, 4, 0, 6, 7, 3, 0, 1, 0, 11, 1, 7, 1, 5, 0, 2, 0, 12, 0, 3, 4, 13, 8, 4, 0, 2]

cp's OEIS Frontend

A243055 Difference between the indices of the smallest and the largest prime dividing n: If n = p_i * ... * p_k, where p_i <= ... <= p_k, where p_h = A000040(h), then a(n) = (k-i), a(1) = 0 by convention.

Table of values

List of values

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

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

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