A338642 - cp's OEIS frontend

A338642 Square spiral of smallest distinct positive integers starting at 1 such that the four sums of each term with its four nearest neighbors are composite numbers.

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

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

cp's OEIS Frontend

A338642 Square spiral of smallest distinct positive integers starting at 1 such that the four sums of each term with its four nearest neighbors are composite numbers.

Table of values

List of values

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

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

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