A181687 - cp's OEIS frontend

A181687 Numbers n such that the number of odd divisors of (2n)^2 is an odd divisor of (2n)^2, and the number of even divisors of (2n)^2 is an even divisor of (2n)^2.

n	a(n)
1	1
2	2
3	3
4	6
5	8
6	12
7	15
8	21
9	24
10	25
11	30
12	33
13	39
14	42
15	45
16	50
17	51
18	57
19	66
20	69
21	75
22	78
23	81
24	87
25	90
26	93
27	96
28	102
29	111
30	114
31	120
32	123
33	128
34	129
35	138
36	141
37	150
38	159
39	162
40	168
41	174
42	177
43	180
44	183
45	186
46	189
47	200
48	201
49	213
50	219
51	222
52	225
53	237
54	240
55	246
56	249
57	258
58	264
59	267
60	282
61	291
62	300

[1, 2, 3, 6, 8, 12, 15, 21, 24, 25, 30, 33, 39, 42, 45, 50, 51, 57, 66, 69, 75, 78, 81, 87, 90, 93, 96, 102, 111, 114, 120, 123, 128, 129, 138, 141, 150, 159, 162, 168, 174, 177, 180, 183, 186, 189, 200, 201, 213, 219, 222, 225, 237, 240, 246, 249, 258, 264, 267, 282, 291, 300]

cp's OEIS Frontend

A181687 Numbers n such that the number of odd divisors of (2n)^2 is an odd divisor of (2n)^2, and the number of even divisors of (2n)^2 is an even divisor of (2n)^2.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	6
5	8
6	12
7	15
8	21
9	24
10	25
11	30
12	33
13	39
14	42
15	45
16	50
17	51
18	57
19	66
20	69
21	75
22	78
23	81
24	87
25	90
26	93
27	96
28	102
29	111
30	114
31	120
32	123
33	128
34	129
35	138
36	141
37	150
38	159
39	162
40	168
41	174
42	177
43	180
44	183
45	186
46	189
47	200
48	201
49	213
50	219
51	222
52	225
53	237
54	240
55	246
56	249
57	258
58	264
59	267
60	282
61	291
62	300

n	a(n)
1	1
2	2
3	3
4	6
5	8
6	12
7	15
8	21
9	24
10	25
11	30
12	33
13	39
14	42
15	45
16	50
17	51
18	57
19	66
20	69
21	75
22	78
23	81
24	87
25	90
26	93
27	96
28	102
29	111
30	114
31	120
32	123
33	128
34	129
35	138
36	141
37	150
38	159
39	162
40	168
41	174
42	177
43	180
44	183
45	186
46	189
47	200
48	201
49	213
50	219
51	222
52	225
53	237
54	240
55	246
56	249
57	258
58	264
59	267
60	282
61	291
62	300

n	a(n)
1	1
2	2
3	3
4	6
5	8
6	12
7	15
8	21
9	24
10	25
11	30
12	33
13	39
14	42
15	45
16	50
17	51
18	57
19	66
20	69
21	75
22	78
23	81
24	87
25	90
26	93
27	96
28	102
29	111
30	114
31	120
32	123
33	128
34	129
35	138
36	141
37	150
38	159
39	162
40	168
41	174
42	177
43	180
44	183
45	186
46	189
47	200
48	201
49	213
50	219
51	222
52	225
53	237
54	240
55	246
56	249
57	258
58	264
59	267
60	282
61	291
62	300