A331400 - cp's OEIS frontend

A331400 The grid points visible from the central point of an infinite 2D square lattice where all grid points are numbered as in the Ulam spiral.

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	8
8	9
9	10
10	12
11	14
12	16
13	18
14	20
15	22
16	24
17	26
18	27
19	29
20	30
21	32
22	33
23	35
24	36
25	38
26	39
27	41
28	42
29	44
30	45
31	47
32	48
33	50
34	52
35	54
36	56
37	58
38	60
39	62
40	64
41	66
42	68
43	70
44	72
45	74
46	76
47	78
48	80
49	82
50	83
51	84
52	85
53	87
54	88
55	89
56	90
57	92
58	93
59	94
60	95
61	97
62	98
63	99
64	100
65	102
66	103
67	104
68	105
69	107
70	108
71	109
72	110
73	112
74	113
75	114
76	115

[2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 22, 24, 26, 27, 29, 30, 32, 33, 35, 36, 38, 39, 41, 42, 44, 45, 47, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 83, 84, 85, 87, 88, 89, 90, 92, 93, 94, 95, 97, 98, 99, 100, 102, 103, 104, 105, 107, 108, 109, 110, 112, 113, 114, 115]

cp's OEIS Frontend

A331400 The grid points visible from the central point of an infinite 2D square lattice where all grid points are numbered as in the Ulam spiral.

Table of values

List of values

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	8
8	9
9	10
10	12
11	14
12	16
13	18
14	20
15	22
16	24
17	26
18	27
19	29
20	30
21	32
22	33
23	35
24	36
25	38
26	39
27	41
28	42
29	44
30	45
31	47
32	48
33	50
34	52
35	54
36	56
37	58
38	60
39	62
40	64
41	66
42	68
43	70
44	72
45	74
46	76
47	78
48	80
49	82
50	83
51	84
52	85
53	87
54	88
55	89
56	90
57	92
58	93
59	94
60	95
61	97
62	98
63	99
64	100
65	102
66	103
67	104
68	105
69	107
70	108
71	109
72	110
73	112
74	113
75	114
76	115

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	8
8	9
9	10
10	12
11	14
12	16
13	18
14	20
15	22
16	24
17	26
18	27
19	29
20	30
21	32
22	33
23	35
24	36
25	38
26	39
27	41
28	42
29	44
30	45
31	47
32	48
33	50
34	52
35	54
36	56
37	58
38	60
39	62
40	64
41	66
42	68
43	70
44	72
45	74
46	76
47	78
48	80
49	82
50	83
51	84
52	85
53	87
54	88
55	89
56	90
57	92
58	93
59	94
60	95
61	97
62	98
63	99
64	100
65	102
66	103
67	104
68	105
69	107
70	108
71	109
72	110
73	112
74	113
75	114
76	115

n	a(n)
1	2
2	3
3	4
4	5
5	6
6	7
7	8
8	9
9	10
10	12
11	14
12	16
13	18
14	20
15	22
16	24
17	26
18	27
19	29
20	30
21	32
22	33
23	35
24	36
25	38
26	39
27	41
28	42
29	44
30	45
31	47
32	48
33	50
34	52
35	54
36	56
37	58
38	60
39	62
40	64
41	66
42	68
43	70
44	72
45	74
46	76
47	78
48	80
49	82
50	83
51	84
52	85
53	87
54	88
55	89
56	90
57	92
58	93
59	94
60	95
61	97
62	98
63	99
64	100
65	102
66	103
67	104
68	105
69	107
70	108
71	109
72	110
73	112
74	113
75	114
76	115