A072963 - cp's OEIS frontend

A072963 In prime factorization of n replace all single (i.e., non-twin) primes with 1.

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

[1, 1, 3, 1, 5, 3, 7, 1, 9, 5, 11, 3, 13, 7, 15, 1, 17, 9, 19, 5, 21, 11, 1, 3, 25, 13, 27, 7, 29, 15, 31, 1, 33, 17, 35, 9, 1, 19, 39, 5, 41, 21, 43, 11, 45, 1, 1, 3, 49, 25, 51, 13, 1, 27, 55, 7, 57, 29, 59, 15, 61, 31, 63, 1, 65, 33, 1, 17, 3, 35, 71, 9, 73, 1, 75, 19, 77, 39, 1, 5, 81]

cp's OEIS Frontend

A072963 In prime factorization of n replace all single (i.e., non-twin) primes with 1.

Table of values

List of values

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

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

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