A049283 - cp's OEIS frontend

A049283 a(n) is the smallest k such that phi(k) = n, where phi is Euler's totient function, or a(n) = 0 if no such k exists.

n	a(n)
1	1
2	3
3	0
4	5
5	0
6	7
7	0
8	15
9	0
10	11
11	0
12	13
13	0
14	0
15	0
16	17
17	0
18	19
19	0
20	25
21	0
22	23
23	0
24	35
25	0
26	0
27	0
28	29
29	0
30	31
31	0
32	51
33	0
34	0
35	0
36	37
37	0
38	0
39	0
40	41
41	0
42	43
43	0
44	69
45	0
46	47
47	0
48	65
49	0
50	0
51	0
52	53
53	0
54	81
55	0
56	87
57	0
58	59
59	0
60	61
61	0
62	0
63	0
64	85
65	0
66	67
67	0
68	0
69	0
70	71
71	0
72	73
73	0
74	0
75	0
76	0
77	0
78	79
79	0
80	123
81	0
82	83
83	0
84	129
85	0
86	0
87	0
88	89

[1, 3, 0, 5, 0, 7, 0, 15, 0, 11, 0, 13, 0, 0, 0, 17, 0, 19, 0, 25, 0, 23, 0, 35, 0, 0, 0, 29, 0, 31, 0, 51, 0, 0, 0, 37, 0, 0, 0, 41, 0, 43, 0, 69, 0, 47, 0, 65, 0, 0, 0, 53, 0, 81, 0, 87, 0, 59, 0, 61, 0, 0, 0, 85, 0, 67, 0, 0, 0, 71, 0, 73, 0, 0, 0, 0, 0, 79, 0, 123, 0, 83, 0, 129, 0, 0, 0, 89]

cp's OEIS Frontend

A049283 a(n) is the smallest k such that phi(k) = n, where phi is Euler's totient function, or a(n) = 0 if no such k exists.

Table of values

List of values

n	a(n)
1	1
2	3
3	0
4	5
5	0
6	7
7	0
8	15
9	0
10	11
11	0
12	13
13	0
14	0
15	0
16	17
17	0
18	19
19	0
20	25
21	0
22	23
23	0
24	35
25	0
26	0
27	0
28	29
29	0
30	31
31	0
32	51
33	0
34	0
35	0
36	37
37	0
38	0
39	0
40	41
41	0
42	43
43	0
44	69
45	0
46	47
47	0
48	65
49	0
50	0
51	0
52	53
53	0
54	81
55	0
56	87
57	0
58	59
59	0
60	61
61	0
62	0
63	0
64	85
65	0
66	67
67	0
68	0
69	0
70	71
71	0
72	73
73	0
74	0
75	0
76	0
77	0
78	79
79	0
80	123
81	0
82	83
83	0
84	129
85	0
86	0
87	0
88	89

n	a(n)
1	1
2	3
3	0
4	5
5	0
6	7
7	0
8	15
9	0
10	11
11	0
12	13
13	0
14	0
15	0
16	17
17	0
18	19
19	0
20	25
21	0
22	23
23	0
24	35
25	0
26	0
27	0
28	29
29	0
30	31
31	0
32	51
33	0
34	0
35	0
36	37
37	0
38	0
39	0
40	41
41	0
42	43
43	0
44	69
45	0
46	47
47	0
48	65
49	0
50	0
51	0
52	53
53	0
54	81
55	0
56	87
57	0
58	59
59	0
60	61
61	0
62	0
63	0
64	85
65	0
66	67
67	0
68	0
69	0
70	71
71	0
72	73
73	0
74	0
75	0
76	0
77	0
78	79
79	0
80	123
81	0
82	83
83	0
84	129
85	0
86	0
87	0
88	89

n	a(n)
1	1
2	3
3	0
4	5
5	0
6	7
7	0
8	15
9	0
10	11
11	0
12	13
13	0
14	0
15	0
16	17
17	0
18	19
19	0
20	25
21	0
22	23
23	0
24	35
25	0
26	0
27	0
28	29
29	0
30	31
31	0
32	51
33	0
34	0
35	0
36	37
37	0
38	0
39	0
40	41
41	0
42	43
43	0
44	69
45	0
46	47
47	0
48	65
49	0
50	0
51	0
52	53
53	0
54	81
55	0
56	87
57	0
58	59
59	0
60	61
61	0
62	0
63	0
64	85
65	0
66	67
67	0
68	0
69	0
70	71
71	0
72	73
73	0
74	0
75	0
76	0
77	0
78	79
79	0
80	123
81	0
82	83
83	0
84	129
85	0
86	0
87	0
88	89