A346786 - cp's OEIS frontend

A346786 If a(n) is prime, then a(n) + a(n+1) is prime; if a(n) is not prime, then a(n) + a(n+1) is not prime. This is also true for pairs of consecutive digits: if the first one is prime, the sum of the pair is also prime; if the first one is nonprime, the sum of the pair is nonprime. This is the lexicographically earliest sequence of distinct terms > 0 with this property.

n	a(n)
1	2
2	1
3	3
4	4
5	5
6	6
7	8
8	7
9	40
10	9
11	13
12	46
13	20
14	10
15	15
16	21
17	30
18	18
19	17
20	42
21	32
22	19
23	34
24	23
25	44
26	25
27	29
28	38
29	48
30	45
31	60
32	62
33	50
34	64
35	52
36	56
37	63
38	80
39	66
40	68
41	70
42	82
43	58
44	74
45	69
46	76
47	84
48	81
49	87
50	401
51	86
52	88
53	100
54	90
55	93
56	201
57	91
58	95
59	200
60	96
61	99
62	97
63	406
64	204
65	206
66	208
67	101
68	300

[2, 1, 3, 4, 5, 6, 8, 7, 40, 9, 13, 46, 20, 10, 15, 21, 30, 18, 17, 42, 32, 19, 34, 23, 44, 25, 29, 38, 48, 45, 60, 62, 50, 64, 52, 56, 63, 80, 66, 68, 70, 82, 58, 74, 69, 76, 84, 81, 87, 401, 86, 88, 100, 90, 93, 201, 91, 95, 200, 96, 99, 97, 406, 204, 206, 208, 101, 300]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
1	2
2	1
3	3
4	4
5	5
6	6
7	8
8	7
9	40
10	9
11	13
12	46
13	20
14	10
15	15
16	21
17	30
18	18
19	17
20	42
21	32
22	19
23	34
24	23
25	44
26	25
27	29
28	38
29	48
30	45
31	60
32	62
33	50
34	64
35	52
36	56
37	63
38	80
39	66
40	68
41	70
42	82
43	58
44	74
45	69
46	76
47	84
48	81
49	87
50	401
51	86
52	88
53	100
54	90
55	93
56	201
57	91
58	95
59	200
60	96
61	99
62	97
63	406
64	204
65	206
66	208
67	101
68	300

n	a(n)
1	2
2	1
3	3
4	4
5	5
6	6
7	8
8	7
9	40
10	9
11	13
12	46
13	20
14	10
15	15
16	21
17	30
18	18
19	17
20	42
21	32
22	19
23	34
24	23
25	44
26	25
27	29
28	38
29	48
30	45
31	60
32	62
33	50
34	64
35	52
36	56
37	63
38	80
39	66
40	68
41	70
42	82
43	58
44	74
45	69
46	76
47	84
48	81
49	87
50	401
51	86
52	88
53	100
54	90
55	93
56	201
57	91
58	95
59	200
60	96
61	99
62	97
63	406
64	204
65	206
66	208
67	101
68	300

n	a(n)
1	2
2	1
3	3
4	4
5	5
6	6
7	8
8	7
9	40
10	9
11	13
12	46
13	20
14	10
15	15
16	21
17	30
18	18
19	17
20	42
21	32
22	19
23	34
24	23
25	44
26	25
27	29
28	38
29	48
30	45
31	60
32	62
33	50
34	64
35	52
36	56
37	63
38	80
39	66
40	68
41	70
42	82
43	58
44	74
45	69
46	76
47	84
48	81
49	87
50	401
51	86
52	88
53	100
54	90
55	93
56	201
57	91
58	95
59	200
60	96
61	99
62	97
63	406
64	204
65	206
66	208
67	101
68	300