A378636 - cp's OEIS frontend

A378636 Irregular triangle read by rows: row n lists all m <= n such that phi(m) divides n, where phi is the Euler totient function (A000010).

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

[1, 1, 2, 1, 2, 1, 2, 3, 4, 1, 2, 1, 2, 3, 4, 6, 1, 2, 1, 2, 3, 4, 5, 6, 8, 1, 2, 1, 2, 3, 4, 6, 1, 2, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 1, 2, 1, 2, 3, 4, 6, 1, 2, 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 1, 2, 1, 2, 3, 4, 6, 7, 9, 14, 18, 1, 2, 1, 2, 3, 4, 5, 6, 8, 10, 11, 12]

cp's OEIS Frontend

A378636 Irregular triangle read by rows: row n lists all m <= n such that phi(m) divides n, where phi is the Euler totient function (A000010).

Table of values

List of values

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

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

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