A118020 - cp's OEIS frontend

A118020 Number of steps to reach an integer starting with (n+1)/n and using the approximate cubing map x -> x*ceiling(x^2); or -1 if no integer is ever reached.

n	a(n)
1	0
2	-1
3	3
4	-1
5	12
6	2
7	3
8	-1
9	7
10	2
11	18
12	8
13	7
14	22
15	3
16	-1
17	6
18	8
19	17
20	-1
21	25
22	3
23	68
24	4
25	8
26	14
27	3
28	11
29	171
30	6
31	19
32	5
33	11
34	11
35	16
36	6
37	23
38	19
39	6
40	-1
41	55
42	3
43	23
44	10
45	4
46	26
47	58
48	6
49	12
50	3
51	13
52	3
53	62
54	9
55	9
56	4
57	19
58	62
59	105
60	9
61	7
62	24
63	7
64	-1
65	3
66	17
67	16
68	12
69	66
70	21
71	66
72	-1
73	63
74	65
75	6
76	28
77	20
78	20
79	54
80	-1
81	13
82	92
83	19
84	21
85	7
86	9
87	34
88	36
89	67
90	5
91	20
92	5
93	29
94	62
95	39
96	6
97	105

[0, -1, 3, -1, 12, 2, 3, -1, 7, 2, 18, 8, 7, 22, 3, -1, 6, 8, 17, -1, 25, 3, 68, 4, 8, 14, 3, 11, 171, 6, 19, 5, 11, 11, 16, 6, 23, 19, 6, -1, 55, 3, 23, 10, 4, 26, 58, 6, 12, 3, 13, 3, 62, 9, 9, 4, 19, 62, 105, 9, 7, 24, 7, -1, 3, 17, 16, 12, 66, 21, 66, -1, 63, 65, 6, 28, 20, 20, 54, -1, 13, 92, 19, 21, 7, 9, 34, 36, 67, 5, 20, 5, 29, 62, 39, 6, 105]

cp's OEIS Frontend

A118020 Number of steps to reach an integer starting with (n+1)/n and using the approximate cubing map x -> x*ceiling(x^2); or -1 if no integer is ever reached.

Table of values

List of values

n	a(n)
1	0
2	-1
3	3
4	-1
5	12
6	2
7	3
8	-1
9	7
10	2
11	18
12	8
13	7
14	22
15	3
16	-1
17	6
18	8
19	17
20	-1
21	25
22	3
23	68
24	4
25	8
26	14
27	3
28	11
29	171
30	6
31	19
32	5
33	11
34	11
35	16
36	6
37	23
38	19
39	6
40	-1
41	55
42	3
43	23
44	10
45	4
46	26
47	58
48	6
49	12
50	3
51	13
52	3
53	62
54	9
55	9
56	4
57	19
58	62
59	105
60	9
61	7
62	24
63	7
64	-1
65	3
66	17
67	16
68	12
69	66
70	21
71	66
72	-1
73	63
74	65
75	6
76	28
77	20
78	20
79	54
80	-1
81	13
82	92
83	19
84	21
85	7
86	9
87	34
88	36
89	67
90	5
91	20
92	5
93	29
94	62
95	39
96	6
97	105

n	a(n)
1	0
2	-1
3	3
4	-1
5	12
6	2
7	3
8	-1
9	7
10	2
11	18
12	8
13	7
14	22
15	3
16	-1
17	6
18	8
19	17
20	-1
21	25
22	3
23	68
24	4
25	8
26	14
27	3
28	11
29	171
30	6
31	19
32	5
33	11
34	11
35	16
36	6
37	23
38	19
39	6
40	-1
41	55
42	3
43	23
44	10
45	4
46	26
47	58
48	6
49	12
50	3
51	13
52	3
53	62
54	9
55	9
56	4
57	19
58	62
59	105
60	9
61	7
62	24
63	7
64	-1
65	3
66	17
67	16
68	12
69	66
70	21
71	66
72	-1
73	63
74	65
75	6
76	28
77	20
78	20
79	54
80	-1
81	13
82	92
83	19
84	21
85	7
86	9
87	34
88	36
89	67
90	5
91	20
92	5
93	29
94	62
95	39
96	6
97	105

n	a(n)
1	0
2	-1
3	3
4	-1
5	12
6	2
7	3
8	-1
9	7
10	2
11	18
12	8
13	7
14	22
15	3
16	-1
17	6
18	8
19	17
20	-1
21	25
22	3
23	68
24	4
25	8
26	14
27	3
28	11
29	171
30	6
31	19
32	5
33	11
34	11
35	16
36	6
37	23
38	19
39	6
40	-1
41	55
42	3
43	23
44	10
45	4
46	26
47	58
48	6
49	12
50	3
51	13
52	3
53	62
54	9
55	9
56	4
57	19
58	62
59	105
60	9
61	7
62	24
63	7
64	-1
65	3
66	17
67	16
68	12
69	66
70	21
71	66
72	-1
73	63
74	65
75	6
76	28
77	20
78	20
79	54
80	-1
81	13
82	92
83	19
84	21
85	7
86	9
87	34
88	36
89	67
90	5
91	20
92	5
93	29
94	62
95	39
96	6
97	105