A291485 - cp's OEIS frontend

A291485 Numbers m such that sigma(x) = m*(m+1)/2 has at least one solution.

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	12
8	13
9	15
10	18
11	20
12	24
13	27
14	30
15	31
16	32
17	35
18	38
19	39
20	47
21	48
22	51
23	55
24	56
25	62
26	63
27	64
28	79
29	80
30	84
31	90
32	92
33	95
34	96
35	104
36	111
37	116
38	119
39	120
40	128
41	135
42	140
43	142
44	143
45	144
46	147
47	152
48	155
49	156
50	159
51	160
52	167
53	168
54	170
55	171
56	175
57	176
58	182
59	184
60	188
61	191
62	192
63	195
64	203
65	207
66	208

[1, 2, 3, 5, 7, 8, 12, 13, 15, 18, 20, 24, 27, 30, 31, 32, 35, 38, 39, 47, 48, 51, 55, 56, 62, 63, 64, 79, 80, 84, 90, 92, 95, 96, 104, 111, 116, 119, 120, 128, 135, 140, 142, 143, 144, 147, 152, 155, 156, 159, 160, 167, 168, 170, 171, 175, 176, 182, 184, 188, 191, 192, 195, 203, 207, 208]

cp's OEIS Frontend

A291485 Numbers m such that sigma(x) = m*(m+1)/2 has at least one solution.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	12
8	13
9	15
10	18
11	20
12	24
13	27
14	30
15	31
16	32
17	35
18	38
19	39
20	47
21	48
22	51
23	55
24	56
25	62
26	63
27	64
28	79
29	80
30	84
31	90
32	92
33	95
34	96
35	104
36	111
37	116
38	119
39	120
40	128
41	135
42	140
43	142
44	143
45	144
46	147
47	152
48	155
49	156
50	159
51	160
52	167
53	168
54	170
55	171
56	175
57	176
58	182
59	184
60	188
61	191
62	192
63	195
64	203
65	207
66	208

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	12
8	13
9	15
10	18
11	20
12	24
13	27
14	30
15	31
16	32
17	35
18	38
19	39
20	47
21	48
22	51
23	55
24	56
25	62
26	63
27	64
28	79
29	80
30	84
31	90
32	92
33	95
34	96
35	104
36	111
37	116
38	119
39	120
40	128
41	135
42	140
43	142
44	143
45	144
46	147
47	152
48	155
49	156
50	159
51	160
52	167
53	168
54	170
55	171
56	175
57	176
58	182
59	184
60	188
61	191
62	192
63	195
64	203
65	207
66	208

n	a(n)
1	1
2	2
3	3
4	5
5	7
6	8
7	12
8	13
9	15
10	18
11	20
12	24
13	27
14	30
15	31
16	32
17	35
18	38
19	39
20	47
21	48
22	51
23	55
24	56
25	62
26	63
27	64
28	79
29	80
30	84
31	90
32	92
33	95
34	96
35	104
36	111
37	116
38	119
39	120
40	128
41	135
42	140
43	142
44	143
45	144
46	147
47	152
48	155
49	156
50	159
51	160
52	167
53	168
54	170
55	171
56	175
57	176
58	182
59	184
60	188
61	191
62	192
63	195
64	203
65	207
66	208