A033559 - cp's OEIS frontend

A033559 a(n) = (q - p)/2, where p is the largest prime < n and q is the smallest prime > n.

n	a(n)
4	1
5	2
6	1
7	3
8	2
9	2
10	2
11	3
12	1
13	3
14	2
15	2
16	2
17	3
18	1
19	3
20	2
21	2
22	2
23	5
24	3
25	3
26	3
27	3
28	3
29	4
30	1
31	4
32	3
33	3
34	3
35	3
36	3
37	5
38	2
39	2
40	2
41	3
42	1
43	3
44	2
45	2
46	2
47	5
48	3
49	3
50	3
51	3
52	3
53	6
54	3
55	3
56	3
57	3
58	3
59	4
60	1
61	4
62	3
63	3
64	3
65	3
66	3
67	5
68	2
69	2
70	2
71	3
72	1
73	4
74	3
75	3
76	3
77	3
78	3
79	5
80	2
81	2
82	2
83	5
84	3
85	3
86	3
87	3
88	3
89	7
90	4
91	4
92	4
93	4
94	4
95	4
96	4
97	6
98	2
99	2
100	2

[1, 2, 1, 3, 2, 2, 2, 3, 1, 3, 2, 2, 2, 3, 1, 3, 2, 2, 2, 5, 3, 3, 3, 3, 3, 4, 1, 4, 3, 3, 3, 3, 3, 5, 2, 2, 2, 3, 1, 3, 2, 2, 2, 5, 3, 3, 3, 3, 3, 6, 3, 3, 3, 3, 3, 4, 1, 4, 3, 3, 3, 3, 3, 5, 2, 2, 2, 3, 1, 4, 3, 3, 3, 3, 3, 5, 2, 2, 2, 5, 3, 3, 3, 3, 3, 7, 4, 4, 4, 4, 4, 4, 4, 6, 2, 2, 2]

cp's OEIS Frontend

A033559 a(n) = (q - p)/2, where p is the largest prime < n and q is the smallest prime > n.

Table of values

List of values

n	a(n)
4	1
5	2
6	1
7	3
8	2
9	2
10	2
11	3
12	1
13	3
14	2
15	2
16	2
17	3
18	1
19	3
20	2
21	2
22	2
23	5
24	3
25	3
26	3
27	3
28	3
29	4
30	1
31	4
32	3
33	3
34	3
35	3
36	3
37	5
38	2
39	2
40	2
41	3
42	1
43	3
44	2
45	2
46	2
47	5
48	3
49	3
50	3
51	3
52	3
53	6
54	3
55	3
56	3
57	3
58	3
59	4
60	1
61	4
62	3
63	3
64	3
65	3
66	3
67	5
68	2
69	2
70	2
71	3
72	1
73	4
74	3
75	3
76	3
77	3
78	3
79	5
80	2
81	2
82	2
83	5
84	3
85	3
86	3
87	3
88	3
89	7
90	4
91	4
92	4
93	4
94	4
95	4
96	4
97	6
98	2
99	2
100	2

n	a(n)
4	1
5	2
6	1
7	3
8	2
9	2
10	2
11	3
12	1
13	3
14	2
15	2
16	2
17	3
18	1
19	3
20	2
21	2
22	2
23	5
24	3
25	3
26	3
27	3
28	3
29	4
30	1
31	4
32	3
33	3
34	3
35	3
36	3
37	5
38	2
39	2
40	2
41	3
42	1
43	3
44	2
45	2
46	2
47	5
48	3
49	3
50	3
51	3
52	3
53	6
54	3
55	3
56	3
57	3
58	3
59	4
60	1
61	4
62	3
63	3
64	3
65	3
66	3
67	5
68	2
69	2
70	2
71	3
72	1
73	4
74	3
75	3
76	3
77	3
78	3
79	5
80	2
81	2
82	2
83	5
84	3
85	3
86	3
87	3
88	3
89	7
90	4
91	4
92	4
93	4
94	4
95	4
96	4
97	6
98	2
99	2
100	2

n	a(n)
4	1
5	2
6	1
7	3
8	2
9	2
10	2
11	3
12	1
13	3
14	2
15	2
16	2
17	3
18	1
19	3
20	2
21	2
22	2
23	5
24	3
25	3
26	3
27	3
28	3
29	4
30	1
31	4
32	3
33	3
34	3
35	3
36	3
37	5
38	2
39	2
40	2
41	3
42	1
43	3
44	2
45	2
46	2
47	5
48	3
49	3
50	3
51	3
52	3
53	6
54	3
55	3
56	3
57	3
58	3
59	4
60	1
61	4
62	3
63	3
64	3
65	3
66	3
67	5
68	2
69	2
70	2
71	3
72	1
73	4
74	3
75	3
76	3
77	3
78	3
79	5
80	2
81	2
82	2
83	5
84	3
85	3
86	3
87	3
88	3
89	7
90	4
91	4
92	4
93	4
94	4
95	4
96	4
97	6
98	2
99	2
100	2