A260042 - cp's OEIS frontend

A260042 Numbers k such that (4^k-1)/3 is not squarefree.

n	a(n)
1	9
2	10
3	18
4	20
5	21
6	27
7	30
8	36
9	40
10	42
11	45
12	50
13	54
14	55
15	60
16	63
17	68
18	70
19	72
20	78
21	80
22	81
23	84
24	90
25	99
26	100
27	105
28	108
29	110
30	117
31	120
32	126
33	130
34	135
35	136
36	140
37	144
38	147
39	150
40	153
41	155
42	156
43	160
44	162
45	165
46	168
47	170
48	171
49	180
50	182
51	189
52	190
53	198
54	200
55	204
56	207
57	210

[9, 10, 18, 20, 21, 27, 30, 36, 40, 42, 45, 50, 54, 55, 60, 63, 68, 70, 72, 78, 80, 81, 84, 90, 99, 100, 105, 108, 110, 117, 120, 126, 130, 135, 136, 140, 144, 147, 150, 153, 155, 156, 160, 162, 165, 168, 170, 171, 180, 182, 189, 190, 198, 200, 204, 207, 210]

cp's OEIS Frontend

A260042 Numbers k such that (4^k-1)/3 is not squarefree.

Table of values

List of values

n	a(n)
1	9
2	10
3	18
4	20
5	21
6	27
7	30
8	36
9	40
10	42
11	45
12	50
13	54
14	55
15	60
16	63
17	68
18	70
19	72
20	78
21	80
22	81
23	84
24	90
25	99
26	100
27	105
28	108
29	110
30	117
31	120
32	126
33	130
34	135
35	136
36	140
37	144
38	147
39	150
40	153
41	155
42	156
43	160
44	162
45	165
46	168
47	170
48	171
49	180
50	182
51	189
52	190
53	198
54	200
55	204
56	207
57	210

n	a(n)
1	9
2	10
3	18
4	20
5	21
6	27
7	30
8	36
9	40
10	42
11	45
12	50
13	54
14	55
15	60
16	63
17	68
18	70
19	72
20	78
21	80
22	81
23	84
24	90
25	99
26	100
27	105
28	108
29	110
30	117
31	120
32	126
33	130
34	135
35	136
36	140
37	144
38	147
39	150
40	153
41	155
42	156
43	160
44	162
45	165
46	168
47	170
48	171
49	180
50	182
51	189
52	190
53	198
54	200
55	204
56	207
57	210

n	a(n)
1	9
2	10
3	18
4	20
5	21
6	27
7	30
8	36
9	40
10	42
11	45
12	50
13	54
14	55
15	60
16	63
17	68
18	70
19	72
20	78
21	80
22	81
23	84
24	90
25	99
26	100
27	105
28	108
29	110
30	117
31	120
32	126
33	130
34	135
35	136
36	140
37	144
38	147
39	150
40	153
41	155
42	156
43	160
44	162
45	165
46	168
47	170
48	171
49	180
50	182
51	189
52	190
53	198
54	200
55	204
56	207
57	210