A130892 - cp's OEIS frontend

A130892 a(n) = n if n is not an odd prime number. Otherwise, a(n) = k*ceiling(n/10), where k is the smallest integer such that n < 10^k.

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

[0, 1, 2, 1, 4, 1, 6, 1, 8, 9, 10, 4, 12, 4, 14, 15, 16, 4, 18, 4, 20, 21, 22, 6, 24, 25, 26, 27, 28, 6, 30, 8, 32, 33, 34, 35, 36, 8, 38, 39, 40, 10, 42, 10, 44, 45, 46, 10, 48, 49, 50, 51, 52, 12, 54, 55, 56, 57, 58, 12, 60, 14, 62, 63, 64, 65, 66, 14, 68]

cp's OEIS Frontend

A130892 a(n) = n if n is not an odd prime number. Otherwise, a(n) = k*ceiling(n/10), where k is the smallest integer such that n < 10^k.

Table of values

List of values

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

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

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