A346721 - cp's OEIS frontend

A346721 Use the cells of a hexagonal grid to represent the algebraic integers in the integer ring of Q(sqrt(-7)), as explained in the comments. Number the cells along the counterclockwise hexagonal spiral that starts with cells 0 and 1 representing integers 0 and 1. List the cells that represent 0 or a prime in the ring.

n	a(n)
1	0
2	2
3	3
4	5
5	6
6	11
7	17
8	19
9	21
10	23
11	28
12	30
13	32
14	45
15	47
16	57
17	59
18	61
19	63
20	65
21	67
22	69
23	76
24	78
25	80
26	82
27	84
28	103
29	107
30	121
31	125
32	127
33	129
34	131
35	135
36	137
37	139
38	148
39	150
40	152
41	156
42	158
43	160
44	187
45	189
46	211
47	213

[0, 2, 3, 5, 6, 11, 17, 19, 21, 23, 28, 30, 32, 45, 47, 57, 59, 61, 63, 65, 67, 69, 76, 78, 80, 82, 84, 103, 107, 121, 125, 127, 129, 131, 135, 137, 139, 148, 150, 152, 156, 158, 160, 187, 189, 211, 213]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
1	0
2	2
3	3
4	5
5	6
6	11
7	17
8	19
9	21
10	23
11	28
12	30
13	32
14	45
15	47
16	57
17	59
18	61
19	63
20	65
21	67
22	69
23	76
24	78
25	80
26	82
27	84
28	103
29	107
30	121
31	125
32	127
33	129
34	131
35	135
36	137
37	139
38	148
39	150
40	152
41	156
42	158
43	160
44	187
45	189
46	211
47	213

n	a(n)
1	0
2	2
3	3
4	5
5	6
6	11
7	17
8	19
9	21
10	23
11	28
12	30
13	32
14	45
15	47
16	57
17	59
18	61
19	63
20	65
21	67
22	69
23	76
24	78
25	80
26	82
27	84
28	103
29	107
30	121
31	125
32	127
33	129
34	131
35	135
36	137
37	139
38	148
39	150
40	152
41	156
42	158
43	160
44	187
45	189
46	211
47	213

n	a(n)
1	0
2	2
3	3
4	5
5	6
6	11
7	17
8	19
9	21
10	23
11	28
12	30
13	32
14	45
15	47
16	57
17	59
18	61
19	63
20	65
21	67
22	69
23	76
24	78
25	80
26	82
27	84
28	103
29	107
30	121
31	125
32	127
33	129
34	131
35	135
36	137
37	139
38	148
39	150
40	152
41	156
42	158
43	160
44	187
45	189
46	211
47	213