A039689 - cp's OEIS frontend

A039689 Numbers k such that phi(k) + 1 is not a prime.

n	a(n)
1	15
2	16
3	20
4	24
5	25
6	30
7	33
8	35
9	39
10	44
11	45
12	50
13	51
14	52
15	56
16	64
17	65
18	66
19	68
20	69
21	70
22	72
23	78
24	80
25	81
26	84
27	85
28	87
29	90
30	92
31	96
32	102
33	104
34	105
35	112
36	116
37	120
38	121
39	123
40	128
41	129
42	130
43	136
44	138
45	140
46	141
47	143
48	144
49	147
50	155
51	156
52	159
53	160
54	161
55	162
56	164
57	165
58	168
59	170

[15, 16, 20, 24, 25, 30, 33, 35, 39, 44, 45, 50, 51, 52, 56, 64, 65, 66, 68, 69, 70, 72, 78, 80, 81, 84, 85, 87, 90, 92, 96, 102, 104, 105, 112, 116, 120, 121, 123, 128, 129, 130, 136, 138, 140, 141, 143, 144, 147, 155, 156, 159, 160, 161, 162, 164, 165, 168, 170]

cp's OEIS Frontend

A039689 Numbers k such that phi(k) + 1 is not a prime.

Table of values

List of values

n	a(n)
1	15
2	16
3	20
4	24
5	25
6	30
7	33
8	35
9	39
10	44
11	45
12	50
13	51
14	52
15	56
16	64
17	65
18	66
19	68
20	69
21	70
22	72
23	78
24	80
25	81
26	84
27	85
28	87
29	90
30	92
31	96
32	102
33	104
34	105
35	112
36	116
37	120
38	121
39	123
40	128
41	129
42	130
43	136
44	138
45	140
46	141
47	143
48	144
49	147
50	155
51	156
52	159
53	160
54	161
55	162
56	164
57	165
58	168
59	170

n	a(n)
1	15
2	16
3	20
4	24
5	25
6	30
7	33
8	35
9	39
10	44
11	45
12	50
13	51
14	52
15	56
16	64
17	65
18	66
19	68
20	69
21	70
22	72
23	78
24	80
25	81
26	84
27	85
28	87
29	90
30	92
31	96
32	102
33	104
34	105
35	112
36	116
37	120
38	121
39	123
40	128
41	129
42	130
43	136
44	138
45	140
46	141
47	143
48	144
49	147
50	155
51	156
52	159
53	160
54	161
55	162
56	164
57	165
58	168
59	170

n	a(n)
1	15
2	16
3	20
4	24
5	25
6	30
7	33
8	35
9	39
10	44
11	45
12	50
13	51
14	52
15	56
16	64
17	65
18	66
19	68
20	69
21	70
22	72
23	78
24	80
25	81
26	84
27	85
28	87
29	90
30	92
31	96
32	102
33	104
34	105
35	112
36	116
37	120
38	121
39	123
40	128
41	129
42	130
43	136
44	138
45	140
46	141
47	143
48	144
49	147
50	155
51	156
52	159
53	160
54	161
55	162
56	164
57	165
58	168
59	170