A285719 - cp's OEIS frontend

A285719 a(1) = 1, and for n > 1, a(n) = the largest squarefree number k such that n-k is also squarefree.

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

[1, 1, 2, 3, 3, 5, 6, 7, 7, 7, 10, 11, 11, 13, 14, 15, 15, 17, 17, 19, 19, 21, 22, 23, 23, 23, 26, 26, 26, 29, 30, 31, 31, 33, 34, 35, 35, 37, 38, 39, 39, 41, 42, 43, 43, 43, 46, 47, 47, 47, 46, 51, 51, 53, 53, 55, 55, 57, 58, 59, 59, 61, 62, 62, 62, 65, 66, 67, 67, 69, 70, 71, 71, 73, 74, 74, 74, 77, 78, 79, 79, 79, 82, 83, 83, 85, 86, 87, 87, 89, 89, 91, 91]

cp's OEIS Frontend

A285719 a(1) = 1, and for n > 1, a(n) = the largest squarefree number k such that n-k is also squarefree.

Table of values

List of values

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

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

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