A363247 - cp's OEIS frontend

A363247 a(0) = 0. a(n) = the smallest nonnegative integer, excluding a(n-1), not occurring in all occurrences of a(n-1)'s eight neighbors thus far in a square spiral.

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	1
6	5
7	2
8	4
9	5
10	3
11	6
12	0
13	7
14	1
15	8
16	0
17	9
18	2
19	8
20	6
21	4
22	7
23	8
24	10
25	0
26	11
27	1
28	10
29	2
30	11
31	4
32	12
33	2
34	13
35	3
36	9
37	5
38	12
39	3
40	14
41	0
42	15
43	1
44	14
45	5
46	13
47	4
48	15
49	2
50	16
51	1
52	17
53	0
54	18
55	1
56	19
57	0
58	20
59	1
60	21
61	0
62	22
63	1
64	23
65	0
66	24
67	1
68	25
69	0
70	26
71	1
72	27
73	0
74	28
75	2
76	17
77	3

[0, 1, 2, 3, 4, 1, 5, 2, 4, 5, 3, 6, 0, 7, 1, 8, 0, 9, 2, 8, 6, 4, 7, 8, 10, 0, 11, 1, 10, 2, 11, 4, 12, 2, 13, 3, 9, 5, 12, 3, 14, 0, 15, 1, 14, 5, 13, 4, 15, 2, 16, 1, 17, 0, 18, 1, 19, 0, 20, 1, 21, 0, 22, 1, 23, 0, 24, 1, 25, 0, 26, 1, 27, 0, 28, 2, 17, 3]

cp's OEIS Frontend

A363247 a(0) = 0. a(n) = the smallest nonnegative integer, excluding a(n-1), not occurring in all occurrences of a(n-1)'s eight neighbors thus far in a square spiral.

Table of values

List of values

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	1
6	5
7	2
8	4
9	5
10	3
11	6
12	0
13	7
14	1
15	8
16	0
17	9
18	2
19	8
20	6
21	4
22	7
23	8
24	10
25	0
26	11
27	1
28	10
29	2
30	11
31	4
32	12
33	2
34	13
35	3
36	9
37	5
38	12
39	3
40	14
41	0
42	15
43	1
44	14
45	5
46	13
47	4
48	15
49	2
50	16
51	1
52	17
53	0
54	18
55	1
56	19
57	0
58	20
59	1
60	21
61	0
62	22
63	1
64	23
65	0
66	24
67	1
68	25
69	0
70	26
71	1
72	27
73	0
74	28
75	2
76	17
77	3

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	1
6	5
7	2
8	4
9	5
10	3
11	6
12	0
13	7
14	1
15	8
16	0
17	9
18	2
19	8
20	6
21	4
22	7
23	8
24	10
25	0
26	11
27	1
28	10
29	2
30	11
31	4
32	12
33	2
34	13
35	3
36	9
37	5
38	12
39	3
40	14
41	0
42	15
43	1
44	14
45	5
46	13
47	4
48	15
49	2
50	16
51	1
52	17
53	0
54	18
55	1
56	19
57	0
58	20
59	1
60	21
61	0
62	22
63	1
64	23
65	0
66	24
67	1
68	25
69	0
70	26
71	1
72	27
73	0
74	28
75	2
76	17
77	3

n	a(n)
0	0
1	1
2	2
3	3
4	4
5	1
6	5
7	2
8	4
9	5
10	3
11	6
12	0
13	7
14	1
15	8
16	0
17	9
18	2
19	8
20	6
21	4
22	7
23	8
24	10
25	0
26	11
27	1
28	10
29	2
30	11
31	4
32	12
33	2
34	13
35	3
36	9
37	5
38	12
39	3
40	14
41	0
42	15
43	1
44	14
45	5
46	13
47	4
48	15
49	2
50	16
51	1
52	17
53	0
54	18
55	1
56	19
57	0
58	20
59	1
60	21
61	0
62	22
63	1
64	23
65	0
66	24
67	1
68	25
69	0
70	26
71	1
72	27
73	0
74	28
75	2
76	17
77	3