A328248 - cp's OEIS frontend

A328248 a(n) = 1 if n is a squarefree number (A005117), otherwise a(n) = 1 + number of iterations of arithmetic derivative (A003415) needed to reach a squarefree number, or 0 if no such number is ever reached.

n	a(n)
1	1
2	1
3	1
4	0
5	1
6	1
7	1
8	0
9	2
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	2
19	1
20	0
21	1
22	1
23	1
24	0
25	2
26	1
27	0
28	0
29	1
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	1
39	1
40	0
41	1
42	1
43	1
44	0
45	2
46	1
47	1
48	0
49	2
50	3
51	1
52	0
53	1
54	0
55	1
56	0
57	1
58	1
59	1
60	0
61	1
62	1
63	2
64	0
65	1
66	1
67	1
68	0
69	1
70	1
71	1
72	0
73	1
74	1
75	2
76	0
77	1
78	1
79	1
80	0
81	0
82	1
83	1
84	0
85	1
86	1
87	1
88	0
89	1
90	2
91	1
92	0
93	1
94	1
95	1
96	0
97	1
98	2
99	3
100	0
101	1
102	1
103	1
104	0
105	1
106	1
107	1
108	0
109	1
110	1
111	1
112	0
113	1
114	1
115	1
116	0
117	2
118	1
119	1
120	0

[1, 1, 1, 0, 1, 1, 1, 0, 2, 1, 1, 0, 1, 1, 1, 0, 1, 2, 1, 0, 1, 1, 1, 0, 2, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 2, 1, 1, 0, 2, 3, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 2, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 2, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1, 2, 1, 0, 1, 1, 1, 0, 1, 2, 3, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 2, 1, 1, 0]

cp's OEIS Frontend

A328248 a(n) = 1 if n is a squarefree number (A005117), otherwise a(n) = 1 + number of iterations of arithmetic derivative (A003415) needed to reach a squarefree number, or 0 if no such number is ever reached.

Table of values

List of values

n	a(n)
1	1
2	1
3	1
4	0
5	1
6	1
7	1
8	0
9	2
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	2
19	1
20	0
21	1
22	1
23	1
24	0
25	2
26	1
27	0
28	0
29	1
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	1
39	1
40	0
41	1
42	1
43	1
44	0
45	2
46	1
47	1
48	0
49	2
50	3
51	1
52	0
53	1
54	0
55	1
56	0
57	1
58	1
59	1
60	0
61	1
62	1
63	2
64	0
65	1
66	1
67	1
68	0
69	1
70	1
71	1
72	0
73	1
74	1
75	2
76	0
77	1
78	1
79	1
80	0
81	0
82	1
83	1
84	0
85	1
86	1
87	1
88	0
89	1
90	2
91	1
92	0
93	1
94	1
95	1
96	0
97	1
98	2
99	3
100	0
101	1
102	1
103	1
104	0
105	1
106	1
107	1
108	0
109	1
110	1
111	1
112	0
113	1
114	1
115	1
116	0
117	2
118	1
119	1
120	0

n	a(n)
1	1
2	1
3	1
4	0
5	1
6	1
7	1
8	0
9	2
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	2
19	1
20	0
21	1
22	1
23	1
24	0
25	2
26	1
27	0
28	0
29	1
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	1
39	1
40	0
41	1
42	1
43	1
44	0
45	2
46	1
47	1
48	0
49	2
50	3
51	1
52	0
53	1
54	0
55	1
56	0
57	1
58	1
59	1
60	0
61	1
62	1
63	2
64	0
65	1
66	1
67	1
68	0
69	1
70	1
71	1
72	0
73	1
74	1
75	2
76	0
77	1
78	1
79	1
80	0
81	0
82	1
83	1
84	0
85	1
86	1
87	1
88	0
89	1
90	2
91	1
92	0
93	1
94	1
95	1
96	0
97	1
98	2
99	3
100	0
101	1
102	1
103	1
104	0
105	1
106	1
107	1
108	0
109	1
110	1
111	1
112	0
113	1
114	1
115	1
116	0
117	2
118	1
119	1
120	0

n	a(n)
1	1
2	1
3	1
4	0
5	1
6	1
7	1
8	0
9	2
10	1
11	1
12	0
13	1
14	1
15	1
16	0
17	1
18	2
19	1
20	0
21	1
22	1
23	1
24	0
25	2
26	1
27	0
28	0
29	1
30	1
31	1
32	0
33	1
34	1
35	1
36	0
37	1
38	1
39	1
40	0
41	1
42	1
43	1
44	0
45	2
46	1
47	1
48	0
49	2
50	3
51	1
52	0
53	1
54	0
55	1
56	0
57	1
58	1
59	1
60	0
61	1
62	1
63	2
64	0
65	1
66	1
67	1
68	0
69	1
70	1
71	1
72	0
73	1
74	1
75	2
76	0
77	1
78	1
79	1
80	0
81	0
82	1
83	1
84	0
85	1
86	1
87	1
88	0
89	1
90	2
91	1
92	0
93	1
94	1
95	1
96	0
97	1
98	2
99	3
100	0
101	1
102	1
103	1
104	0
105	1
106	1
107	1
108	0
109	1
110	1
111	1
112	0
113	1
114	1
115	1
116	0
117	2
118	1
119	1
120	0