A351078 - cp's OEIS frontend

A351078 First noncomposite number reached when iterating the map x -> x', when starting from x = n, or 0 if no such number is ever reached. Here x' is the arithmetic derivative of x, A003415.

n	a(n)
0	0
1	1
2	2
3	3
4	0
5	5
6	5
7	7
8	0
9	5
10	7
11	11
12	0
13	13
14	5
15	0
16	0
17	17
18	7
19	19
20	0
21	7
22	13
23	23
24	0
25	7
26	0
27	0
28	0
29	29
30	31
31	31
32	0
33	5
34	19
35	0
36	0
37	37
38	7
39	0
40	0
41	41
42	41
43	43
44	0
45	0
46	7
47	47
48	0
49	5
50	0
51	0
52	0
53	53
54	0
55	0
56	0
57	13
58	31
59	59
60	0
61	61
62	5
63	0
64	0
65	7
66	61
67	67
68	0
69	0
70	59
71	71
72	0
73	73
74	0
75	0
76	0
77	7
78	71
79	79
80	0
81	0
82	43
83	83
84	0
85	13
86	0
87	0
88	0
89	89
90	0
91	0
92	0
93	19
94	5

[0, 1, 2, 3, 0, 5, 5, 7, 0, 5, 7, 11, 0, 13, 5, 0, 0, 17, 7, 19, 0, 7, 13, 23, 0, 7, 0, 0, 0, 29, 31, 31, 0, 5, 19, 0, 0, 37, 7, 0, 0, 41, 41, 43, 0, 0, 7, 47, 0, 5, 0, 0, 0, 53, 0, 0, 0, 13, 31, 59, 0, 61, 5, 0, 0, 7, 61, 67, 0, 0, 59, 71, 0, 73, 0, 0, 0, 7, 71, 79, 0, 0, 43, 83, 0, 13, 0, 0, 0, 89, 0, 0, 0, 19, 5]

cp's OEIS Frontend

A351078 First noncomposite number reached when iterating the map x -> x', when starting from x = n, or 0 if no such number is ever reached. Here x' is the arithmetic derivative of x, A003415.

Table of values

List of values

n	a(n)
0	0
1	1
2	2
3	3
4	0
5	5
6	5
7	7
8	0
9	5
10	7
11	11
12	0
13	13
14	5
15	0
16	0
17	17
18	7
19	19
20	0
21	7
22	13
23	23
24	0
25	7
26	0
27	0
28	0
29	29
30	31
31	31
32	0
33	5
34	19
35	0
36	0
37	37
38	7
39	0
40	0
41	41
42	41
43	43
44	0
45	0
46	7
47	47
48	0
49	5
50	0
51	0
52	0
53	53
54	0
55	0
56	0
57	13
58	31
59	59
60	0
61	61
62	5
63	0
64	0
65	7
66	61
67	67
68	0
69	0
70	59
71	71
72	0
73	73
74	0
75	0
76	0
77	7
78	71
79	79
80	0
81	0
82	43
83	83
84	0
85	13
86	0
87	0
88	0
89	89
90	0
91	0
92	0
93	19
94	5

n	a(n)
0	0
1	1
2	2
3	3
4	0
5	5
6	5
7	7
8	0
9	5
10	7
11	11
12	0
13	13
14	5
15	0
16	0
17	17
18	7
19	19
20	0
21	7
22	13
23	23
24	0
25	7
26	0
27	0
28	0
29	29
30	31
31	31
32	0
33	5
34	19
35	0
36	0
37	37
38	7
39	0
40	0
41	41
42	41
43	43
44	0
45	0
46	7
47	47
48	0
49	5
50	0
51	0
52	0
53	53
54	0
55	0
56	0
57	13
58	31
59	59
60	0
61	61
62	5
63	0
64	0
65	7
66	61
67	67
68	0
69	0
70	59
71	71
72	0
73	73
74	0
75	0
76	0
77	7
78	71
79	79
80	0
81	0
82	43
83	83
84	0
85	13
86	0
87	0
88	0
89	89
90	0
91	0
92	0
93	19
94	5

n	a(n)
0	0
1	1
2	2
3	3
4	0
5	5
6	5
7	7
8	0
9	5
10	7
11	11
12	0
13	13
14	5
15	0
16	0
17	17
18	7
19	19
20	0
21	7
22	13
23	23
24	0
25	7
26	0
27	0
28	0
29	29
30	31
31	31
32	0
33	5
34	19
35	0
36	0
37	37
38	7
39	0
40	0
41	41
42	41
43	43
44	0
45	0
46	7
47	47
48	0
49	5
50	0
51	0
52	0
53	53
54	0
55	0
56	0
57	13
58	31
59	59
60	0
61	61
62	5
63	0
64	0
65	7
66	61
67	67
68	0
69	0
70	59
71	71
72	0
73	73
74	0
75	0
76	0
77	7
78	71
79	79
80	0
81	0
82	43
83	83
84	0
85	13
86	0
87	0
88	0
89	89
90	0
91	0
92	0
93	19
94	5