A346723 - cp's OEIS frontend

A346723 Use the cells of a hexagonal grid to represent the algebraic integers in the integer ring of Q(sqrt(-19)) 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	7
7	8
8	9
9	11
10	13
11	14
12	15
13	17
14	19
15	20
16	21
17	22
18	23
19	25
20	26
21	28
22	29
23	30
24	31
25	32
26	34
27	35
28	39
29	41
30	51
31	53
32	91
33	101
34	109
35	119
36	128
37	129
38	130
39	132
40	134
41	136
42	137
43	138
44	141
45	143
46	144
47	146
48	149
49	150
50	151
51	153
52	155
53	157
54	158
55	159
56	162
57	164
58	165
59	167
60	171
61	175
62	177

[0, 2, 3, 5, 6, 7, 8, 9, 11, 13, 14, 15, 17, 19, 20, 21, 22, 23, 25, 26, 28, 29, 30, 31, 32, 34, 35, 39, 41, 51, 53, 91, 101, 109, 119, 128, 129, 130, 132, 134, 136, 137, 138, 141, 143, 144, 146, 149, 150, 151, 153, 155, 157, 158, 159, 162, 164, 165, 167, 171, 175, 177]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
1	0
2	2
3	3
4	5
5	6
6	7
7	8
8	9
9	11
10	13
11	14
12	15
13	17
14	19
15	20
16	21
17	22
18	23
19	25
20	26
21	28
22	29
23	30
24	31
25	32
26	34
27	35
28	39
29	41
30	51
31	53
32	91
33	101
34	109
35	119
36	128
37	129
38	130
39	132
40	134
41	136
42	137
43	138
44	141
45	143
46	144
47	146
48	149
49	150
50	151
51	153
52	155
53	157
54	158
55	159
56	162
57	164
58	165
59	167
60	171
61	175
62	177

n	a(n)
1	0
2	2
3	3
4	5
5	6
6	7
7	8
8	9
9	11
10	13
11	14
12	15
13	17
14	19
15	20
16	21
17	22
18	23
19	25
20	26
21	28
22	29
23	30
24	31
25	32
26	34
27	35
28	39
29	41
30	51
31	53
32	91
33	101
34	109
35	119
36	128
37	129
38	130
39	132
40	134
41	136
42	137
43	138
44	141
45	143
46	144
47	146
48	149
49	150
50	151
51	153
52	155
53	157
54	158
55	159
56	162
57	164
58	165
59	167
60	171
61	175
62	177

n	a(n)
1	0
2	2
3	3
4	5
5	6
6	7
7	8
8	9
9	11
10	13
11	14
12	15
13	17
14	19
15	20
16	21
17	22
18	23
19	25
20	26
21	28
22	29
23	30
24	31
25	32
26	34
27	35
28	39
29	41
30	51
31	53
32	91
33	101
34	109
35	119
36	128
37	129
38	130
39	132
40	134
41	136
42	137
43	138
44	141
45	143
46	144
47	146
48	149
49	150
50	151
51	153
52	155
53	157
54	158
55	159
56	162
57	164
58	165
59	167
60	171
61	175
62	177