A345435 - cp's OEIS frontend

A345435 Represent the ring of Eisenstein integers E = {x+yomega: x, y rational integers, omega = exp(2Pi*i/3)} by the cells of a hexagonal grid; number the cells of the grid along a counterclockwise hexagonal spiral, with the cells 0, 1 numbered 0, 1. Sequence lists the index numbers of the cells which are 0 or a prime in E.

n	a(n)
1	0
2	7
3	8
4	9
5	10
6	11
7	12
8	13
9	14
10	15
11	16
12	17
13	18
14	19
15	20
16	22
17	23
18	25
19	26
20	28
21	29
22	31
23	32
24	34
25	35
26	37
27	39
28	41
29	43
30	45
31	47
32	49
33	51
34	53
35	55
36	57
37	59
38	62
39	63
40	65
41	67
42	68
43	70
44	72
45	73
46	75
47	77
48	78
49	80
50	82
51	83
52	85
53	87
54	88
55	90
56	91
57	95
58	97
59	101
60	103
61	107
62	109
63	113
64	115

[0, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 23, 25, 26, 28, 29, 31, 32, 34, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 62, 63, 65, 67, 68, 70, 72, 73, 75, 77, 78, 80, 82, 83, 85, 87, 88, 90, 91, 95, 97, 101, 103, 107, 109, 113, 115]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
1	0
2	7
3	8
4	9
5	10
6	11
7	12
8	13
9	14
10	15
11	16
12	17
13	18
14	19
15	20
16	22
17	23
18	25
19	26
20	28
21	29
22	31
23	32
24	34
25	35
26	37
27	39
28	41
29	43
30	45
31	47
32	49
33	51
34	53
35	55
36	57
37	59
38	62
39	63
40	65
41	67
42	68
43	70
44	72
45	73
46	75
47	77
48	78
49	80
50	82
51	83
52	85
53	87
54	88
55	90
56	91
57	95
58	97
59	101
60	103
61	107
62	109
63	113
64	115

n	a(n)
1	0
2	7
3	8
4	9
5	10
6	11
7	12
8	13
9	14
10	15
11	16
12	17
13	18
14	19
15	20
16	22
17	23
18	25
19	26
20	28
21	29
22	31
23	32
24	34
25	35
26	37
27	39
28	41
29	43
30	45
31	47
32	49
33	51
34	53
35	55
36	57
37	59
38	62
39	63
40	65
41	67
42	68
43	70
44	72
45	73
46	75
47	77
48	78
49	80
50	82
51	83
52	85
53	87
54	88
55	90
56	91
57	95
58	97
59	101
60	103
61	107
62	109
63	113
64	115

n	a(n)
1	0
2	7
3	8
4	9
5	10
6	11
7	12
8	13
9	14
10	15
11	16
12	17
13	18
14	19
15	20
16	22
17	23
18	25
19	26
20	28
21	29
22	31
23	32
24	34
25	35
26	37
27	39
28	41
29	43
30	45
31	47
32	49
33	51
34	53
35	55
36	57
37	59
38	62
39	63
40	65
41	67
42	68
43	70
44	72
45	73
46	75
47	77
48	78
49	80
50	82
51	83
52	85
53	87
54	88
55	90
56	91
57	95
58	97
59	101
60	103
61	107
62	109
63	113
64	115