A291503 - cp's OEIS frontend

A291503 a(n) is the smallest k such that sigma(k) = phi(n), or 0 if no such k exists.

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

[1, 1, 0, 0, 3, 0, 5, 3, 5, 3, 0, 3, 6, 5, 7, 7, 0, 5, 10, 7, 6, 0, 0, 7, 19, 6, 10, 6, 12, 7, 29, 0, 19, 0, 14, 6, 22, 10, 14, 0, 27, 6, 20, 19, 14, 0, 0, 0, 20, 19, 21, 14, 0, 10, 27, 14, 22, 12, 0, 0, 24, 29, 22, 21, 33, 19, 0, 21, 43, 14, 0, 14, 30, 22, 27, 22, 24, 14, 45]

cp's OEIS Frontend

A291503 a(n) is the smallest k such that sigma(k) = phi(n), or 0 if no such k exists.

Table of values

List of values

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

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

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