A306807 - cp's OEIS frontend

A306807 An irregular fractal sequence: underline a(n) iff the absolute difference |a(n-1) - a(n)| is prime; all underlined terms rebuild the starting sequence.

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

[1, 2, 3, 1, 5, 2, 6, 3, 1, 7, 5, 2, 8, 6, 3, 1, 9, 7, 5, 2, 10, 8, 6, 3, 1, 11, 9, 7, 5, 2, 12, 10, 8, 6, 3, 1, 13, 11, 9, 7, 5, 2, 14, 12, 10, 8, 6, 3, 1, 15, 13, 11, 9, 7, 5, 2, 16, 14, 12, 10, 8, 6, 3, 1, 17, 15, 13, 11, 9, 7, 5, 2, 18, 16, 14, 12, 10, 8, 6, 3, 1, 19, 17, 15, 13, 11, 9, 7, 5, 2, 20, 18, 16, 14, 12, 10, 8, 6, 3, 1]

cp's OEIS Frontend

A306807 An irregular fractal sequence: underline a(n) iff the absolute difference |a(n-1) - a(n)| is prime; all underlined terms rebuild the starting sequence.

Table of values

List of values

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

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

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