A282194 - cp's OEIS frontend

A282194 a(n) = smallest positive k such that 2*n + 2^k + 1 is composite.

n	a(n)
0	3
1	5
2	2
3	1
4	4
5	2
6	1
7	7
8	2
9	1
10	2
11	1
12	1
13	3
14	2
15	1
16	1
17	2
18	1
19	4
20	2
21	1
22	2
23	1
24	1
25	2
26	1
27	1
28	3
29	2
30	1
31	1
32	2
33	1
34	3
35	2
36	1
37	1
38	2
39	1
40	2
41	1
42	1
43	2
44	1
45	1
46	1
47	2
48	1
49	4
50	2
51	1
52	4
53	2
54	1
55	2
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	2
69	1
70	1
71	1
72	1
73	3
74	2
75	1
76	1
77	2
78	1
79	1
80	2
81	1
82	2
83	1
84	1
85	2
86	1
87	1
88	3
89	2
90	1
91	1
92	1
93	1
94	4
95	2
96	1
97	3
98	2
99	1
100	1
101	1
102	1
103	1
104	2
105	1
106	1
107	1
108	1

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

cp's OEIS Frontend

A282194 a(n) = smallest positive k such that 2*n + 2^k + 1 is composite.

Table of values

List of values

n	a(n)
0	3
1	5
2	2
3	1
4	4
5	2
6	1
7	7
8	2
9	1
10	2
11	1
12	1
13	3
14	2
15	1
16	1
17	2
18	1
19	4
20	2
21	1
22	2
23	1
24	1
25	2
26	1
27	1
28	3
29	2
30	1
31	1
32	2
33	1
34	3
35	2
36	1
37	1
38	2
39	1
40	2
41	1
42	1
43	2
44	1
45	1
46	1
47	2
48	1
49	4
50	2
51	1
52	4
53	2
54	1
55	2
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	2
69	1
70	1
71	1
72	1
73	3
74	2
75	1
76	1
77	2
78	1
79	1
80	2
81	1
82	2
83	1
84	1
85	2
86	1
87	1
88	3
89	2
90	1
91	1
92	1
93	1
94	4
95	2
96	1
97	3
98	2
99	1
100	1
101	1
102	1
103	1
104	2
105	1
106	1
107	1
108	1

n	a(n)
0	3
1	5
2	2
3	1
4	4
5	2
6	1
7	7
8	2
9	1
10	2
11	1
12	1
13	3
14	2
15	1
16	1
17	2
18	1
19	4
20	2
21	1
22	2
23	1
24	1
25	2
26	1
27	1
28	3
29	2
30	1
31	1
32	2
33	1
34	3
35	2
36	1
37	1
38	2
39	1
40	2
41	1
42	1
43	2
44	1
45	1
46	1
47	2
48	1
49	4
50	2
51	1
52	4
53	2
54	1
55	2
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	2
69	1
70	1
71	1
72	1
73	3
74	2
75	1
76	1
77	2
78	1
79	1
80	2
81	1
82	2
83	1
84	1
85	2
86	1
87	1
88	3
89	2
90	1
91	1
92	1
93	1
94	4
95	2
96	1
97	3
98	2
99	1
100	1
101	1
102	1
103	1
104	2
105	1
106	1
107	1
108	1

n	a(n)
0	3
1	5
2	2
3	1
4	4
5	2
6	1
7	7
8	2
9	1
10	2
11	1
12	1
13	3
14	2
15	1
16	1
17	2
18	1
19	4
20	2
21	1
22	2
23	1
24	1
25	2
26	1
27	1
28	3
29	2
30	1
31	1
32	2
33	1
34	3
35	2
36	1
37	1
38	2
39	1
40	2
41	1
42	1
43	2
44	1
45	1
46	1
47	2
48	1
49	4
50	2
51	1
52	4
53	2
54	1
55	2
56	1
57	1
58	1
59	1
60	1
61	1
62	2
63	1
64	2
65	1
66	1
67	3
68	2
69	1
70	1
71	1
72	1
73	3
74	2
75	1
76	1
77	2
78	1
79	1
80	2
81	1
82	2
83	1
84	1
85	2
86	1
87	1
88	3
89	2
90	1
91	1
92	1
93	1
94	4
95	2
96	1
97	3
98	2
99	1
100	1
101	1
102	1
103	1
104	2
105	1
106	1
107	1
108	1