A383020 - cp's OEIS frontend

A383020 G(n) is a graph constructed with nodes labelled with integers n through n+a(n). Edges are drawn between consecutive integers and between integers sharing the same largest prime factor. a(n) is the smallest integer for which G(n) is not planar.

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

[8, 7, 10, 10, 12, 11, 12, 12, 11, 14, 13, 12, 11, 13, 12, 11, 10, 14, 13, 15, 17, 16, 15, 17, 16, 15, 16, 19, 18, 18, 17, 16, 16, 15, 14, 17, 16, 15, 15, 14, 13, 13, 12, 15, 19, 18, 17, 16, 18, 19, 20, 22, 21, 22, 21, 23, 23, 22, 21, 24, 23, 22, 24, 23, 24, 23]

cp's OEIS Frontend

A383020 G(n) is a graph constructed with nodes labelled with integers n through n+a(n). Edges are drawn between consecutive integers and between integers sharing the same largest prime factor. a(n) is the smallest integer for which G(n) is not planar.

Table of values

List of values

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

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

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