A361624 - cp's OEIS frontend

A361624 Number of distinct prime factors in decimal concatenation of integer (n, n-1, ..., 2, 1, 2, ..., n-1, n) = A007942(n).

n	a(n)
1	0
2	2
3	3
4	2
5	5
6	3
7	3
8	4
9	3
10	3
11	3
12	3
13	1
14	4
15	6
16	2
17	2
18	3
19	4
20	7
21	4
22	8
23	2
24	3
25	4
26	6
27	5
28	7
29	5
30	6
31	6
32	3
33	5
34	7
35	4
36	5
37	8
38	5
39	6
40	6
41	3
42	3
43	7
44	7
45	7
46	7
47	10
48	7
49	6
50	6
51	7
52	4
53	5
54	5
55	7

[0, 2, 3, 2, 5, 3, 3, 4, 3, 3, 3, 3, 1, 4, 6, 2, 2, 3, 4, 7, 4, 8, 2, 3, 4, 6, 5, 7, 5, 6, 6, 3, 5, 7, 4, 5, 8, 5, 6, 6, 3, 3, 7, 7, 7, 7, 10, 7, 6, 6, 7, 4, 5, 5, 7]

cp's OEIS Frontend

A361624 Number of distinct prime factors in decimal concatenation of integer (n, n-1, ..., 2, 1, 2, ..., n-1, n) = A007942(n).

Table of values

List of values

n	a(n)
1	0
2	2
3	3
4	2
5	5
6	3
7	3
8	4
9	3
10	3
11	3
12	3
13	1
14	4
15	6
16	2
17	2
18	3
19	4
20	7
21	4
22	8
23	2
24	3
25	4
26	6
27	5
28	7
29	5
30	6
31	6
32	3
33	5
34	7
35	4
36	5
37	8
38	5
39	6
40	6
41	3
42	3
43	7
44	7
45	7
46	7
47	10
48	7
49	6
50	6
51	7
52	4
53	5
54	5
55	7

n	a(n)
1	0
2	2
3	3
4	2
5	5
6	3
7	3
8	4
9	3
10	3
11	3
12	3
13	1
14	4
15	6
16	2
17	2
18	3
19	4
20	7
21	4
22	8
23	2
24	3
25	4
26	6
27	5
28	7
29	5
30	6
31	6
32	3
33	5
34	7
35	4
36	5
37	8
38	5
39	6
40	6
41	3
42	3
43	7
44	7
45	7
46	7
47	10
48	7
49	6
50	6
51	7
52	4
53	5
54	5
55	7

n	a(n)
1	0
2	2
3	3
4	2
5	5
6	3
7	3
8	4
9	3
10	3
11	3
12	3
13	1
14	4
15	6
16	2
17	2
18	3
19	4
20	7
21	4
22	8
23	2
24	3
25	4
26	6
27	5
28	7
29	5
30	6
31	6
32	3
33	5
34	7
35	4
36	5
37	8
38	5
39	6
40	6
41	3
42	3
43	7
44	7
45	7
46	7
47	10
48	7
49	6
50	6
51	7
52	4
53	5
54	5
55	7