A139393 - cp's OEIS frontend

A139393 a(n) = Sum_{i=1..m} e(i) * 10^(m-i) where e(1) <= ... <= e(m) are the nonzero exponents in the prime factorization of n: a representation of the prime signature of n.

n	a(n)
1	0
2	1
3	1
4	2
5	1
6	11
7	1
8	3
9	2
10	11
11	1
12	12
13	1
14	11
15	11
16	4
17	1
18	12
19	1
20	12
21	11
22	11
23	1
24	13
25	2
26	11
27	3
28	12
29	1
30	111
31	1
32	5
33	11
34	11
35	11
36	22
37	1
38	11
39	11
40	13
41	1
42	111
43	1
44	12
45	12
46	11
47	1
48	14
49	2
50	12
51	11
52	12
53	1
54	13
55	11
56	13
57	11
58	11
59	1
60	112
61	1
62	11
63	12
64	6
65	11
66	111
67	1
68	12
69	11
70	111
71	1
72	23
73	1
74	11
75	12
76	12
77	11
78	111

[0, 1, 1, 2, 1, 11, 1, 3, 2, 11, 1, 12, 1, 11, 11, 4, 1, 12, 1, 12, 11, 11, 1, 13, 2, 11, 3, 12, 1, 111, 1, 5, 11, 11, 11, 22, 1, 11, 11, 13, 1, 111, 1, 12, 12, 11, 1, 14, 2, 12, 11, 12, 1, 13, 11, 13, 11, 11, 1, 112, 1, 11, 12, 6, 11, 111, 1, 12, 11, 111, 1, 23, 1, 11, 12, 12, 11, 111]

cp's OEIS Frontend

A139393 a(n) = Sum_{i=1..m} e(i) * 10^(m-i) where e(1) <= ... <= e(m) are the nonzero exponents in the prime factorization of n: a representation of the prime signature of n.

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	2
5	1
6	11
7	1
8	3
9	2
10	11
11	1
12	12
13	1
14	11
15	11
16	4
17	1
18	12
19	1
20	12
21	11
22	11
23	1
24	13
25	2
26	11
27	3
28	12
29	1
30	111
31	1
32	5
33	11
34	11
35	11
36	22
37	1
38	11
39	11
40	13
41	1
42	111
43	1
44	12
45	12
46	11
47	1
48	14
49	2
50	12
51	11
52	12
53	1
54	13
55	11
56	13
57	11
58	11
59	1
60	112
61	1
62	11
63	12
64	6
65	11
66	111
67	1
68	12
69	11
70	111
71	1
72	23
73	1
74	11
75	12
76	12
77	11
78	111

n	a(n)
1	0
2	1
3	1
4	2
5	1
6	11
7	1
8	3
9	2
10	11
11	1
12	12
13	1
14	11
15	11
16	4
17	1
18	12
19	1
20	12
21	11
22	11
23	1
24	13
25	2
26	11
27	3
28	12
29	1
30	111
31	1
32	5
33	11
34	11
35	11
36	22
37	1
38	11
39	11
40	13
41	1
42	111
43	1
44	12
45	12
46	11
47	1
48	14
49	2
50	12
51	11
52	12
53	1
54	13
55	11
56	13
57	11
58	11
59	1
60	112
61	1
62	11
63	12
64	6
65	11
66	111
67	1
68	12
69	11
70	111
71	1
72	23
73	1
74	11
75	12
76	12
77	11
78	111

n	a(n)
1	0
2	1
3	1
4	2
5	1
6	11
7	1
8	3
9	2
10	11
11	1
12	12
13	1
14	11
15	11
16	4
17	1
18	12
19	1
20	12
21	11
22	11
23	1
24	13
25	2
26	11
27	3
28	12
29	1
30	111
31	1
32	5
33	11
34	11
35	11
36	22
37	1
38	11
39	11
40	13
41	1
42	111
43	1
44	12
45	12
46	11
47	1
48	14
49	2
50	12
51	11
52	12
53	1
54	13
55	11
56	13
57	11
58	11
59	1
60	112
61	1
62	11
63	12
64	6
65	11
66	111
67	1
68	12
69	11
70	111
71	1
72	23
73	1
74	11
75	12
76	12
77	11
78	111