A090532 - cp's OEIS frontend

A090532 Let f(n) = n - pi(n). Then a(n) = least number of steps such that f(f(...(n)))=1.

n	a(n)
2	1
3	1
4	2
5	2
6	2
7	2
8	3
9	3
10	3
11	3
12	3
13	3
14	4
15	4
16	4
17	4
18	4
19	4
20	4
21	4
22	5
23	5
24	5
25	5
26	5
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	6
36	6
37	6
38	6
39	6
40	6
41	6
42	6
43	6
44	6
45	6
46	6
47	6
48	7
49	7
50	7
51	7
52	7
53	7
54	7
55	7
56	7
57	7
58	7
59	7
60	7
61	7
62	7
63	7
64	7
65	7
66	8
67	8
68	8
69	8
70	8
71	8
72	8
73	8
74	8
75	8
76	8
77	8
78	8
79	8
80	8
81	8
82	8
83	8
84	8
85	8
86	8
87	8
88	8
89	8
90	9
91	9
92	9
93	9
94	9
95	9
96	9
97	9
98	9
99	9
100	9
101	9
102	9
103	9
104	9
105	9
106	9

[1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9]

cp's OEIS Frontend

A090532 Let f(n) = n - pi(n). Then a(n) = least number of steps such that f(f(...(n)))=1.

Table of values

List of values

n	a(n)
2	1
3	1
4	2
5	2
6	2
7	2
8	3
9	3
10	3
11	3
12	3
13	3
14	4
15	4
16	4
17	4
18	4
19	4
20	4
21	4
22	5
23	5
24	5
25	5
26	5
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	6
36	6
37	6
38	6
39	6
40	6
41	6
42	6
43	6
44	6
45	6
46	6
47	6
48	7
49	7
50	7
51	7
52	7
53	7
54	7
55	7
56	7
57	7
58	7
59	7
60	7
61	7
62	7
63	7
64	7
65	7
66	8
67	8
68	8
69	8
70	8
71	8
72	8
73	8
74	8
75	8
76	8
77	8
78	8
79	8
80	8
81	8
82	8
83	8
84	8
85	8
86	8
87	8
88	8
89	8
90	9
91	9
92	9
93	9
94	9
95	9
96	9
97	9
98	9
99	9
100	9
101	9
102	9
103	9
104	9
105	9
106	9

n	a(n)
2	1
3	1
4	2
5	2
6	2
7	2
8	3
9	3
10	3
11	3
12	3
13	3
14	4
15	4
16	4
17	4
18	4
19	4
20	4
21	4
22	5
23	5
24	5
25	5
26	5
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	6
36	6
37	6
38	6
39	6
40	6
41	6
42	6
43	6
44	6
45	6
46	6
47	6
48	7
49	7
50	7
51	7
52	7
53	7
54	7
55	7
56	7
57	7
58	7
59	7
60	7
61	7
62	7
63	7
64	7
65	7
66	8
67	8
68	8
69	8
70	8
71	8
72	8
73	8
74	8
75	8
76	8
77	8
78	8
79	8
80	8
81	8
82	8
83	8
84	8
85	8
86	8
87	8
88	8
89	8
90	9
91	9
92	9
93	9
94	9
95	9
96	9
97	9
98	9
99	9
100	9
101	9
102	9
103	9
104	9
105	9
106	9

n	a(n)
2	1
3	1
4	2
5	2
6	2
7	2
8	3
9	3
10	3
11	3
12	3
13	3
14	4
15	4
16	4
17	4
18	4
19	4
20	4
21	4
22	5
23	5
24	5
25	5
26	5
27	5
28	5
29	5
30	5
31	5
32	5
33	6
34	6
35	6
36	6
37	6
38	6
39	6
40	6
41	6
42	6
43	6
44	6
45	6
46	6
47	6
48	7
49	7
50	7
51	7
52	7
53	7
54	7
55	7
56	7
57	7
58	7
59	7
60	7
61	7
62	7
63	7
64	7
65	7
66	8
67	8
68	8
69	8
70	8
71	8
72	8
73	8
74	8
75	8
76	8
77	8
78	8
79	8
80	8
81	8
82	8
83	8
84	8
85	8
86	8
87	8
88	8
89	8
90	9
91	9
92	9
93	9
94	9
95	9
96	9
97	9
98	9
99	9
100	9
101	9
102	9
103	9
104	9
105	9
106	9