A387720 - cp's OEIS frontend

A387720 Numbers k for which A107758(k) < 2*k, where A107758 is sigma+, multiplicative function with a(p^e) = 1+sigma(p^e).

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	17
9	19
10	23
11	25
12	27
13	29
14	31
15	33
16	35
17	37
18	39
19	41
20	43
21	47
22	49
23	51
24	53
25	55
26	57
27	59
28	61
29	65
30	67
31	69
32	71
33	73
34	77
35	79
36	81
37	83
38	85
39	87
40	89
41	91
42	93
43	95
44	97
45	99
46	101
47	103
48	107
49	109
50	111
51	113
52	115
53	117
54	119
55	121
56	123
57	125
58	127
59	129
60	131
61	133
62	137
63	139
64	141
65	143
66	145
67	147
68	149
69	151
70	153
71	155
72	157
73	159

[1, 3, 5, 7, 9, 11, 13, 17, 19, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 47, 49, 51, 53, 55, 57, 59, 61, 65, 67, 69, 71, 73, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 101, 103, 107, 109, 111, 113, 115, 117, 119, 121, 123, 125, 127, 129, 131, 133, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157, 159]

cp's OEIS Frontend

A387720 Numbers k for which A107758(k) < 2*k, where A107758 is sigma+, multiplicative function with a(p^e) = 1+sigma(p^e).

Table of values

List of values

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	17
9	19
10	23
11	25
12	27
13	29
14	31
15	33
16	35
17	37
18	39
19	41
20	43
21	47
22	49
23	51
24	53
25	55
26	57
27	59
28	61
29	65
30	67
31	69
32	71
33	73
34	77
35	79
36	81
37	83
38	85
39	87
40	89
41	91
42	93
43	95
44	97
45	99
46	101
47	103
48	107
49	109
50	111
51	113
52	115
53	117
54	119
55	121
56	123
57	125
58	127
59	129
60	131
61	133
62	137
63	139
64	141
65	143
66	145
67	147
68	149
69	151
70	153
71	155
72	157
73	159

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	17
9	19
10	23
11	25
12	27
13	29
14	31
15	33
16	35
17	37
18	39
19	41
20	43
21	47
22	49
23	51
24	53
25	55
26	57
27	59
28	61
29	65
30	67
31	69
32	71
33	73
34	77
35	79
36	81
37	83
38	85
39	87
40	89
41	91
42	93
43	95
44	97
45	99
46	101
47	103
48	107
49	109
50	111
51	113
52	115
53	117
54	119
55	121
56	123
57	125
58	127
59	129
60	131
61	133
62	137
63	139
64	141
65	143
66	145
67	147
68	149
69	151
70	153
71	155
72	157
73	159

n	a(n)
1	1
2	3
3	5
4	7
5	9
6	11
7	13
8	17
9	19
10	23
11	25
12	27
13	29
14	31
15	33
16	35
17	37
18	39
19	41
20	43
21	47
22	49
23	51
24	53
25	55
26	57
27	59
28	61
29	65
30	67
31	69
32	71
33	73
34	77
35	79
36	81
37	83
38	85
39	87
40	89
41	91
42	93
43	95
44	97
45	99
46	101
47	103
48	107
49	109
50	111
51	113
52	115
53	117
54	119
55	121
56	123
57	125
58	127
59	129
60	131
61	133
62	137
63	139
64	141
65	143
66	145
67	147
68	149
69	151
70	153
71	155
72	157
73	159