A258742 - cp's OEIS frontend

A258742 With a(1) = 1, a(n) is the smallest positive number not already in the sequence such that a(n)^2 + a(n-1)^2 is not prime.

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

[1, 3, 4, 2, 6, 7, 5, 9, 8, 10, 11, 12, 14, 13, 15, 16, 17, 19, 18, 20, 21, 22, 24, 23, 25, 27, 26, 28, 29, 31, 32, 30, 33, 34, 36, 37, 35, 38, 39, 41, 40, 42, 44, 43, 45, 46, 47, 49, 48, 50, 52, 51, 53, 54, 55, 56, 57, 58, 59, 60, 62, 61, 63, 64, 65, 67, 66, 68, 69, 71, 72, 70, 73, 74, 75, 76, 77, 78, 79, 81]

cp's OEIS Frontend

A258742 With a(1) = 1, a(n) is the smallest positive number not already in the sequence such that a(n)^2 + a(n-1)^2 is not prime.

Table of values

List of values

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

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

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