A060610 - cp's OEIS frontend

A060610 Repeatedly apply Euler phi to the n-th prime; a(n) is the number of terms in the resulting iteration chain which are not powers of 2 (number of initial iterations until reaching the first power of 2).

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	2
7	1
8	3
9	3
10	3
11	2
12	3
13	2
14	3
15	4
16	3
17	4
18	2
19	3
20	3
21	3
22	3
23	3
24	3
25	2
26	3
27	2
28	4
29	4
30	3
31	4
32	3
33	2
34	4
35	4
36	3
37	3
38	5
39	4
40	4
41	4
42	3
43	4
44	2
45	4
46	3
47	3
48	4
49	4
50	4
51	4
52	3
53	2
54	4
55	1
56	4
57	4
58	4
59	4
60	3
61	5
62	4
63	3
64	3
65	3
66	4
67	3
68	3
69	5
70	4
71	3
72	5
73	3
74	3
75	5
76	5
77	3
78	3
79	3
80	2
81	4
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	4
90	3
91	5
92	4
93	6
94	4
95	4
96	5
97	5
98	3
99	4
100	4
101	4
102	5
103	4
104	4
105	4

[0, 1, 1, 2, 2, 2, 1, 3, 3, 3, 2, 3, 2, 3, 4, 3, 4, 2, 3, 3, 3, 3, 3, 3, 2, 3, 2, 4, 4, 3, 4, 3, 2, 4, 4, 3, 3, 5, 4, 4, 4, 3, 4, 2, 4, 3, 3, 4, 4, 4, 4, 3, 2, 4, 1, 4, 4, 4, 4, 3, 5, 4, 3, 3, 3, 4, 3, 3, 5, 4, 3, 5, 3, 3, 5, 5, 3, 3, 3, 2, 4, 3, 4, 4, 4, 3, 3, 4, 4, 3, 5, 4, 6, 4, 4, 5, 5, 3, 4, 4, 4, 5, 4, 4, 4]

cp's OEIS Frontend

A060610 Repeatedly apply Euler phi to the n-th prime; a(n) is the number of terms in the resulting iteration chain which are not powers of 2 (number of initial iterations until reaching the first power of 2).

Table of values

List of values

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	2
7	1
8	3
9	3
10	3
11	2
12	3
13	2
14	3
15	4
16	3
17	4
18	2
19	3
20	3
21	3
22	3
23	3
24	3
25	2
26	3
27	2
28	4
29	4
30	3
31	4
32	3
33	2
34	4
35	4
36	3
37	3
38	5
39	4
40	4
41	4
42	3
43	4
44	2
45	4
46	3
47	3
48	4
49	4
50	4
51	4
52	3
53	2
54	4
55	1
56	4
57	4
58	4
59	4
60	3
61	5
62	4
63	3
64	3
65	3
66	4
67	3
68	3
69	5
70	4
71	3
72	5
73	3
74	3
75	5
76	5
77	3
78	3
79	3
80	2
81	4
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	4
90	3
91	5
92	4
93	6
94	4
95	4
96	5
97	5
98	3
99	4
100	4
101	4
102	5
103	4
104	4
105	4

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	2
7	1
8	3
9	3
10	3
11	2
12	3
13	2
14	3
15	4
16	3
17	4
18	2
19	3
20	3
21	3
22	3
23	3
24	3
25	2
26	3
27	2
28	4
29	4
30	3
31	4
32	3
33	2
34	4
35	4
36	3
37	3
38	5
39	4
40	4
41	4
42	3
43	4
44	2
45	4
46	3
47	3
48	4
49	4
50	4
51	4
52	3
53	2
54	4
55	1
56	4
57	4
58	4
59	4
60	3
61	5
62	4
63	3
64	3
65	3
66	4
67	3
68	3
69	5
70	4
71	3
72	5
73	3
74	3
75	5
76	5
77	3
78	3
79	3
80	2
81	4
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	4
90	3
91	5
92	4
93	6
94	4
95	4
96	5
97	5
98	3
99	4
100	4
101	4
102	5
103	4
104	4
105	4

n	a(n)
1	0
2	1
3	1
4	2
5	2
6	2
7	1
8	3
9	3
10	3
11	2
12	3
13	2
14	3
15	4
16	3
17	4
18	2
19	3
20	3
21	3
22	3
23	3
24	3
25	2
26	3
27	2
28	4
29	4
30	3
31	4
32	3
33	2
34	4
35	4
36	3
37	3
38	5
39	4
40	4
41	4
42	3
43	4
44	2
45	4
46	3
47	3
48	4
49	4
50	4
51	4
52	3
53	2
54	4
55	1
56	4
57	4
58	4
59	4
60	3
61	5
62	4
63	3
64	3
65	3
66	4
67	3
68	3
69	5
70	4
71	3
72	5
73	3
74	3
75	5
76	5
77	3
78	3
79	3
80	2
81	4
82	3
83	4
84	4
85	4
86	3
87	3
88	4
89	4
90	3
91	5
92	4
93	6
94	4
95	4
96	5
97	5
98	3
99	4
100	4
101	4
102	5
103	4
104	4
105	4