A285328 - cp's OEIS frontend

A285328 a(n) = 1 if n is squarefree (A005117), otherwise a(n) = Max {m < n | same prime factors as n, ignoring multiplicity}.

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

[1, 1, 1, 2, 1, 1, 1, 4, 3, 1, 1, 6, 1, 1, 1, 8, 1, 12, 1, 10, 1, 1, 1, 18, 5, 1, 9, 14, 1, 1, 1, 16, 1, 1, 1, 24, 1, 1, 1, 20, 1, 1, 1, 22, 15, 1, 1, 36, 7, 40, 1, 26, 1, 48, 1, 28, 1, 1, 1, 30, 1, 1, 21, 32, 1, 1, 1, 34, 1, 1, 1, 54, 1, 1, 45, 38, 1, 1, 1, 50, 27, 1, 1, 42, 1, 1, 1, 44, 1, 60, 1, 46, 1, 1, 1, 72, 1, 56, 33, 80, 1, 1, 1, 52, 1, 1, 1, 96]

cp's OEIS Frontend

A285328 a(n) = 1 if n is squarefree (A005117), otherwise a(n) = Max {m < n | same prime factors as n, ignoring multiplicity}.

Table of values

List of values

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

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

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