A175431 - cp's OEIS frontend

A175431 Numbers m such that sigma(m) is not a nontrivial power, i.e., sigma(m) = A000203(n) is not equal a^b where a and b are greater than 1.

n	a(n)
1	1
2	2
3	4
4	5
5	6
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	15
14	16
15	17
16	18
17	19
18	20
19	23
20	24
21	25
22	26
23	27
24	28
25	29
26	30
27	32
28	33
29	34
30	35
31	36
32	37
33	38
34	39
35	40
36	41
37	42
38	43
39	44
40	45
41	46
42	47
43	48
44	49
45	50
46	51
47	52
48	53
49	54
50	55
51	56
52	57
53	58
54	59
55	60
56	61
57	62
58	63
59	64
60	65
61	67
62	68
63	69
64	71
65	72
66	73
67	74
68	75
69	76
70	77
71	78
72	79

[1, 2, 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 23, 24, 25, 26, 27, 28, 29, 30, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 68, 69, 71, 72, 73, 74, 75, 76, 77, 78, 79]

cp's OEIS Frontend

A175431 Numbers m such that sigma(m) is not a nontrivial power, i.e., sigma(m) = A000203(n) is not equal a^b where a and b are greater than 1.

Table of values

List of values

n	a(n)
1	1
2	2
3	4
4	5
5	6
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	15
14	16
15	17
16	18
17	19
18	20
19	23
20	24
21	25
22	26
23	27
24	28
25	29
26	30
27	32
28	33
29	34
30	35
31	36
32	37
33	38
34	39
35	40
36	41
37	42
38	43
39	44
40	45
41	46
42	47
43	48
44	49
45	50
46	51
47	52
48	53
49	54
50	55
51	56
52	57
53	58
54	59
55	60
56	61
57	62
58	63
59	64
60	65
61	67
62	68
63	69
64	71
65	72
66	73
67	74
68	75
69	76
70	77
71	78
72	79

n	a(n)
1	1
2	2
3	4
4	5
5	6
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	15
14	16
15	17
16	18
17	19
18	20
19	23
20	24
21	25
22	26
23	27
24	28
25	29
26	30
27	32
28	33
29	34
30	35
31	36
32	37
33	38
34	39
35	40
36	41
37	42
38	43
39	44
40	45
41	46
42	47
43	48
44	49
45	50
46	51
47	52
48	53
49	54
50	55
51	56
52	57
53	58
54	59
55	60
56	61
57	62
58	63
59	64
60	65
61	67
62	68
63	69
64	71
65	72
66	73
67	74
68	75
69	76
70	77
71	78
72	79

n	a(n)
1	1
2	2
3	4
4	5
5	6
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	15
14	16
15	17
16	18
17	19
18	20
19	23
20	24
21	25
22	26
23	27
24	28
25	29
26	30
27	32
28	33
29	34
30	35
31	36
32	37
33	38
34	39
35	40
36	41
37	42
38	43
39	44
40	45
41	46
42	47
43	48
44	49
45	50
46	51
47	52
48	53
49	54
50	55
51	56
52	57
53	58
54	59
55	60
56	61
57	62
58	63
59	64
60	65
61	67
62	68
63	69
64	71
65	72
66	73
67	74
68	75
69	76
70	77
71	78
72	79