A308505 - cp's OEIS frontend

A308505 Counterclockwise square spiral of distinct positive integers constructed by greedy algorithm, such that for p = 2 and 3, every multiple of p (except p itself) is vertically or horizontally adjacent to a cell already holding a multiple of p.

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	11
7	13
8	17
9	4
10	8
11	10
12	6
13	9
14	15
15	19
16	23
17	25
18	29
19	31
20	35
21	37
22	41
23	43
24	14
25	16
26	20
27	22
28	26
29	12
30	18
31	21
32	27
33	33
34	39
35	45
36	47
37	49
38	53
39	55
40	59
41	61
42	65
43	67
44	71
45	73
46	77
47	28
48	32
49	34
50	38
51	40
52	44
53	46
54	24
55	30
56	36
57	42
58	48
59	50
60	51
61	57
62	63
63	69
64	75
65	79
66	83
67	85

[1, 2, 3, 5, 7, 11, 13, 17, 4, 8, 10, 6, 9, 15, 19, 23, 25, 29, 31, 35, 37, 41, 43, 14, 16, 20, 22, 26, 12, 18, 21, 27, 33, 39, 45, 47, 49, 53, 55, 59, 61, 65, 67, 71, 73, 77, 28, 32, 34, 38, 40, 44, 46, 24, 30, 36, 42, 48, 50, 51, 57, 63, 69, 75, 79, 83, 85]

cp's OEIS Frontend

A308505 Counterclockwise square spiral of distinct positive integers constructed by greedy algorithm, such that for p = 2 and 3, every multiple of p (except p itself) is vertically or horizontally adjacent to a cell already holding a multiple of p.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	11
7	13
8	17
9	4
10	8
11	10
12	6
13	9
14	15
15	19
16	23
17	25
18	29
19	31
20	35
21	37
22	41
23	43
24	14
25	16
26	20
27	22
28	26
29	12
30	18
31	21
32	27
33	33
34	39
35	45
36	47
37	49
38	53
39	55
40	59
41	61
42	65
43	67
44	71
45	73
46	77
47	28
48	32
49	34
50	38
51	40
52	44
53	46
54	24
55	30
56	36
57	42
58	48
59	50
60	51
61	57
62	63
63	69
64	75
65	79
66	83
67	85

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	11
7	13
8	17
9	4
10	8
11	10
12	6
13	9
14	15
15	19
16	23
17	25
18	29
19	31
20	35
21	37
22	41
23	43
24	14
25	16
26	20
27	22
28	26
29	12
30	18
31	21
32	27
33	33
34	39
35	45
36	47
37	49
38	53
39	55
40	59
41	61
42	65
43	67
44	71
45	73
46	77
47	28
48	32
49	34
50	38
51	40
52	44
53	46
54	24
55	30
56	36
57	42
58	48
59	50
60	51
61	57
62	63
63	69
64	75
65	79
66	83
67	85

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	11
7	13
8	17
9	4
10	8
11	10
12	6
13	9
14	15
15	19
16	23
17	25
18	29
19	31
20	35
21	37
22	41
23	43
24	14
25	16
26	20
27	22
28	26
29	12
30	18
31	21
32	27
33	33
34	39
35	45
36	47
37	49
38	53
39	55
40	59
41	61
42	65
43	67
44	71
45	73
46	77
47	28
48	32
49	34
50	38
51	40
52	44
53	46
54	24
55	30
56	36
57	42
58	48
59	50
60	51
61	57
62	63
63	69
64	75
65	79
66	83
67	85