A066705 - cp's OEIS frontend

A066705 Greatest k < n such that phi(k) = phi(n) if such k exists, otherwise 0.

n	a(n)
1	0
2	1
3	0
4	3
5	0
6	4
7	0
8	5
9	7
10	8
11	0
12	10
13	0
14	9
15	0
16	15
17	0
18	14
19	0
20	16
21	13
22	11
23	0
24	20
25	0
26	21
27	19
28	26
29	0
30	24
31	0
32	17
33	25
34	32
35	0
36	28
37	0
38	27
39	35
40	34
41	0
42	36
43	0
44	33
45	39
46	23
47	0
48	40
49	43
50	44
51	0
52	45
53	0
54	38
55	41
56	52
57	37
58	29
59	0
60	48
61	0
62	31
63	57
64	51
65	0
66	50
67	0
68	64
69	0
70	56
71	0
72	70
73	0
74	63
75	55
76	74
77	61
78	72
79	0
80	68
81	0

[0, 1, 0, 3, 0, 4, 0, 5, 7, 8, 0, 10, 0, 9, 0, 15, 0, 14, 0, 16, 13, 11, 0, 20, 0, 21, 19, 26, 0, 24, 0, 17, 25, 32, 0, 28, 0, 27, 35, 34, 0, 36, 0, 33, 39, 23, 0, 40, 43, 44, 0, 45, 0, 38, 41, 52, 37, 29, 0, 48, 0, 31, 57, 51, 0, 50, 0, 64, 0, 56, 0, 70, 0, 63, 55, 74, 61, 72, 0, 68, 0]

cp's OEIS Frontend

A066705 Greatest k < n such that phi(k) = phi(n) if such k exists, otherwise 0.

Table of values

List of values

n	a(n)
1	0
2	1
3	0
4	3
5	0
6	4
7	0
8	5
9	7
10	8
11	0
12	10
13	0
14	9
15	0
16	15
17	0
18	14
19	0
20	16
21	13
22	11
23	0
24	20
25	0
26	21
27	19
28	26
29	0
30	24
31	0
32	17
33	25
34	32
35	0
36	28
37	0
38	27
39	35
40	34
41	0
42	36
43	0
44	33
45	39
46	23
47	0
48	40
49	43
50	44
51	0
52	45
53	0
54	38
55	41
56	52
57	37
58	29
59	0
60	48
61	0
62	31
63	57
64	51
65	0
66	50
67	0
68	64
69	0
70	56
71	0
72	70
73	0
74	63
75	55
76	74
77	61
78	72
79	0
80	68
81	0

n	a(n)
1	0
2	1
3	0
4	3
5	0
6	4
7	0
8	5
9	7
10	8
11	0
12	10
13	0
14	9
15	0
16	15
17	0
18	14
19	0
20	16
21	13
22	11
23	0
24	20
25	0
26	21
27	19
28	26
29	0
30	24
31	0
32	17
33	25
34	32
35	0
36	28
37	0
38	27
39	35
40	34
41	0
42	36
43	0
44	33
45	39
46	23
47	0
48	40
49	43
50	44
51	0
52	45
53	0
54	38
55	41
56	52
57	37
58	29
59	0
60	48
61	0
62	31
63	57
64	51
65	0
66	50
67	0
68	64
69	0
70	56
71	0
72	70
73	0
74	63
75	55
76	74
77	61
78	72
79	0
80	68
81	0

n	a(n)
1	0
2	1
3	0
4	3
5	0
6	4
7	0
8	5
9	7
10	8
11	0
12	10
13	0
14	9
15	0
16	15
17	0
18	14
19	0
20	16
21	13
22	11
23	0
24	20
25	0
26	21
27	19
28	26
29	0
30	24
31	0
32	17
33	25
34	32
35	0
36	28
37	0
38	27
39	35
40	34
41	0
42	36
43	0
44	33
45	39
46	23
47	0
48	40
49	43
50	44
51	0
52	45
53	0
54	38
55	41
56	52
57	37
58	29
59	0
60	48
61	0
62	31
63	57
64	51
65	0
66	50
67	0
68	64
69	0
70	56
71	0
72	70
73	0
74	63
75	55
76	74
77	61
78	72
79	0
80	68
81	0