A075773 - cp's OEIS frontend

A075773 Let {b(n)} be the sequence of perfect powers (A001597); then a(n) = max { b(n)-b(n-1), b(n+1)-b(n) }.

n	a(n)
1	3
2	4
3	4
4	7
5	9
6	9
7	5
8	5
9	13
10	15
11	17
12	19
13	21
14	21
15	4
16	16
17	25
18	27
19	27
20	20
21	18
22	18
23	33
24	35
25	35
26	19
27	39
28	41
29	43
30	43
31	28
32	47
33	49
34	51
35	53
36	55
37	57
38	59
39	61
40	61
41	39
42	65
43	67
44	69
45	71
46	71
47	38
48	75
49	77
50	79
51	81
52	81
53	47
54	85
55	87
56	89
57	89
58	68
59	71
60	71
61	12
62	95
63	97
64	99
65	101
66	103
67	103

[3, 4, 4, 7, 9, 9, 5, 5, 13, 15, 17, 19, 21, 21, 4, 16, 25, 27, 27, 20, 18, 18, 33, 35, 35, 19, 39, 41, 43, 43, 28, 47, 49, 51, 53, 55, 57, 59, 61, 61, 39, 65, 67, 69, 71, 71, 38, 75, 77, 79, 81, 81, 47, 85, 87, 89, 89, 68, 71, 71, 12, 95, 97, 99, 101, 103, 103]

cp's OEIS Frontend

A075773 Let {b(n)} be the sequence of perfect powers (A001597); then a(n) = max { b(n)-b(n-1), b(n+1)-b(n) }.

Table of values

List of values

n	a(n)
1	3
2	4
3	4
4	7
5	9
6	9
7	5
8	5
9	13
10	15
11	17
12	19
13	21
14	21
15	4
16	16
17	25
18	27
19	27
20	20
21	18
22	18
23	33
24	35
25	35
26	19
27	39
28	41
29	43
30	43
31	28
32	47
33	49
34	51
35	53
36	55
37	57
38	59
39	61
40	61
41	39
42	65
43	67
44	69
45	71
46	71
47	38
48	75
49	77
50	79
51	81
52	81
53	47
54	85
55	87
56	89
57	89
58	68
59	71
60	71
61	12
62	95
63	97
64	99
65	101
66	103
67	103

n	a(n)
1	3
2	4
3	4
4	7
5	9
6	9
7	5
8	5
9	13
10	15
11	17
12	19
13	21
14	21
15	4
16	16
17	25
18	27
19	27
20	20
21	18
22	18
23	33
24	35
25	35
26	19
27	39
28	41
29	43
30	43
31	28
32	47
33	49
34	51
35	53
36	55
37	57
38	59
39	61
40	61
41	39
42	65
43	67
44	69
45	71
46	71
47	38
48	75
49	77
50	79
51	81
52	81
53	47
54	85
55	87
56	89
57	89
58	68
59	71
60	71
61	12
62	95
63	97
64	99
65	101
66	103
67	103

n	a(n)
1	3
2	4
3	4
4	7
5	9
6	9
7	5
8	5
9	13
10	15
11	17
12	19
13	21
14	21
15	4
16	16
17	25
18	27
19	27
20	20
21	18
22	18
23	33
24	35
25	35
26	19
27	39
28	41
29	43
30	43
31	28
32	47
33	49
34	51
35	53
36	55
37	57
38	59
39	61
40	61
41	39
42	65
43	67
44	69
45	71
46	71
47	38
48	75
49	77
50	79
51	81
52	81
53	47
54	85
55	87
56	89
57	89
58	68
59	71
60	71
61	12
62	95
63	97
64	99
65	101
66	103
67	103