A253215 - cp's OEIS frontend

A253215 a(n) is the greatest positive integer m such that phi(m) <= n where phi is Euler's totient function.

n	a(n)
1	2
2	6
3	6
4	12
5	12
6	18
7	18
8	30
9	30
10	30
11	30
12	42
13	42
14	42
15	42
16	60
17	60
18	60
19	60
20	66
21	66
22	66
23	66
24	90
25	90
26	90
27	90
28	90
29	90
30	90
31	90
32	120
33	120
34	120
35	120
36	126
37	126
38	126
39	126
40	150
41	150
42	150
43	150
44	150
45	150
46	150
47	150
48	210
49	210
50	210
51	210
52	210
53	210
54	210
55	210

[2, 6, 6, 12, 12, 18, 18, 30, 30, 30, 30, 42, 42, 42, 42, 60, 60, 60, 60, 66, 66, 66, 66, 90, 90, 90, 90, 90, 90, 90, 90, 120, 120, 120, 120, 126, 126, 126, 126, 150, 150, 150, 150, 150, 150, 150, 150, 210, 210, 210, 210, 210, 210, 210, 210]

cp's OEIS Frontend

A253215 a(n) is the greatest positive integer m such that phi(m) <= n where phi is Euler's totient function.

Table of values

List of values

n	a(n)
1	2
2	6
3	6
4	12
5	12
6	18
7	18
8	30
9	30
10	30
11	30
12	42
13	42
14	42
15	42
16	60
17	60
18	60
19	60
20	66
21	66
22	66
23	66
24	90
25	90
26	90
27	90
28	90
29	90
30	90
31	90
32	120
33	120
34	120
35	120
36	126
37	126
38	126
39	126
40	150
41	150
42	150
43	150
44	150
45	150
46	150
47	150
48	210
49	210
50	210
51	210
52	210
53	210
54	210
55	210

n	a(n)
1	2
2	6
3	6
4	12
5	12
6	18
7	18
8	30
9	30
10	30
11	30
12	42
13	42
14	42
15	42
16	60
17	60
18	60
19	60
20	66
21	66
22	66
23	66
24	90
25	90
26	90
27	90
28	90
29	90
30	90
31	90
32	120
33	120
34	120
35	120
36	126
37	126
38	126
39	126
40	150
41	150
42	150
43	150
44	150
45	150
46	150
47	150
48	210
49	210
50	210
51	210
52	210
53	210
54	210
55	210

n	a(n)
1	2
2	6
3	6
4	12
5	12
6	18
7	18
8	30
9	30
10	30
11	30
12	42
13	42
14	42
15	42
16	60
17	60
18	60
19	60
20	66
21	66
22	66
23	66
24	90
25	90
26	90
27	90
28	90
29	90
30	90
31	90
32	120
33	120
34	120
35	120
36	126
37	126
38	126
39	126
40	150
41	150
42	150
43	150
44	150
45	150
46	150
47	150
48	210
49	210
50	210
51	210
52	210
53	210
54	210
55	210