A303936 - cp's OEIS frontend

A303936 A fractal-like sequence: erasing all pairs of contiguous terms that do not sum up to a prime leaves the sequence unchanged.

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

[1, 2, 3, 4, 5, 6, 8, 9, 7, 4, 13, 11, 12, 10, 19, 14, 5, 6, 17, 15, 8, 9, 20, 16, 7, 4, 13, 18, 21, 22, 23, 24, 25, 28, 26, 11, 12, 29, 27, 10, 19, 34, 30, 31, 32, 35, 33, 14, 5, 6, 17, 36, 38, 15, 8, 9, 20, 39, 37, 16, 7, 4, 13, 18, 41, 40, 21, 22, 45, 42, 47]

cp's OEIS Frontend

A303936 A fractal-like sequence: erasing all pairs of contiguous terms that do not sum up to a prime leaves the sequence unchanged.

Table of values

List of values

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

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

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