A331304 - cp's OEIS frontend

A331304 For n <= 4, a(n) = n, for n > 4, if n is prime, a(n) = 3 + 2*A000035(A000720(n)), otherwise a(n) = 3 + n - A000720(n).

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	3
8	7
9	8
10	9
11	5
12	10
13	3
14	11
15	12
16	13
17	5
18	14
19	3
20	15
21	16
22	17
23	5
24	18
25	19
26	20
27	21
28	22
29	3
30	23
31	5
32	24
33	25
34	26
35	27
36	28
37	3
38	29
39	30
40	31
41	5
42	32
43	3
44	33
45	34
46	35
47	5
48	36
49	37
50	38
51	39
52	40
53	3
54	41
55	42
56	43
57	44
58	45
59	5
60	46
61	3
62	47
63	48
64	49
65	50
66	51
67	5
68	52
69	53
70	54
71	3
72	55
73	5
74	56
75	57
76	58
77	59
78	60
79	3
80	61
81	62
82	63
83	5
84	64
85	65
86	66
87	67
88	68
89	3
90	69
91	70
92	71
93	72
94	73
95	74
96	75
97	5
98	76
99	77
100	78
101	3
102	79
103	5
104	80
105	81

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

cp's OEIS Frontend

A331304 For n <= 4, a(n) = n, for n > 4, if n is prime, a(n) = 3 + 2*A000035(A000720(n)), otherwise a(n) = 3 + n - A000720(n).

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	3
8	7
9	8
10	9
11	5
12	10
13	3
14	11
15	12
16	13
17	5
18	14
19	3
20	15
21	16
22	17
23	5
24	18
25	19
26	20
27	21
28	22
29	3
30	23
31	5
32	24
33	25
34	26
35	27
36	28
37	3
38	29
39	30
40	31
41	5
42	32
43	3
44	33
45	34
46	35
47	5
48	36
49	37
50	38
51	39
52	40
53	3
54	41
55	42
56	43
57	44
58	45
59	5
60	46
61	3
62	47
63	48
64	49
65	50
66	51
67	5
68	52
69	53
70	54
71	3
72	55
73	5
74	56
75	57
76	58
77	59
78	60
79	3
80	61
81	62
82	63
83	5
84	64
85	65
86	66
87	67
88	68
89	3
90	69
91	70
92	71
93	72
94	73
95	74
96	75
97	5
98	76
99	77
100	78
101	3
102	79
103	5
104	80
105	81

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	3
8	7
9	8
10	9
11	5
12	10
13	3
14	11
15	12
16	13
17	5
18	14
19	3
20	15
21	16
22	17
23	5
24	18
25	19
26	20
27	21
28	22
29	3
30	23
31	5
32	24
33	25
34	26
35	27
36	28
37	3
38	29
39	30
40	31
41	5
42	32
43	3
44	33
45	34
46	35
47	5
48	36
49	37
50	38
51	39
52	40
53	3
54	41
55	42
56	43
57	44
58	45
59	5
60	46
61	3
62	47
63	48
64	49
65	50
66	51
67	5
68	52
69	53
70	54
71	3
72	55
73	5
74	56
75	57
76	58
77	59
78	60
79	3
80	61
81	62
82	63
83	5
84	64
85	65
86	66
87	67
88	68
89	3
90	69
91	70
92	71
93	72
94	73
95	74
96	75
97	5
98	76
99	77
100	78
101	3
102	79
103	5
104	80
105	81

n	a(n)
1	1
2	2
3	3
4	4
5	5
6	6
7	3
8	7
9	8
10	9
11	5
12	10
13	3
14	11
15	12
16	13
17	5
18	14
19	3
20	15
21	16
22	17
23	5
24	18
25	19
26	20
27	21
28	22
29	3
30	23
31	5
32	24
33	25
34	26
35	27
36	28
37	3
38	29
39	30
40	31
41	5
42	32
43	3
44	33
45	34
46	35
47	5
48	36
49	37
50	38
51	39
52	40
53	3
54	41
55	42
56	43
57	44
58	45
59	5
60	46
61	3
62	47
63	48
64	49
65	50
66	51
67	5
68	52
69	53
70	54
71	3
72	55
73	5
74	56
75	57
76	58
77	59
78	60
79	3
80	61
81	62
82	63
83	5
84	64
85	65
86	66
87	67
88	68
89	3
90	69
91	70
92	71
93	72
94	73
95	74
96	75
97	5
98	76
99	77
100	78
101	3
102	79
103	5
104	80
105	81