A117831 - cp's OEIS frontend

A117831 Let S_n be the infinite sequence formed by starting with n and repeatedly reversing the digits and adding 4 to get the next term. Sequence gives number of steps for S_n to reach a cycle, or -1 if no cycle is ever reached.

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

[1, 1, 40, 7, 0, 0, 39, 6, 0, 0, 38, 5, 0, 18, 37, 3, 0, 43, 10, 0, 4, 42, 9, 4, 4, 41, 7, 0, 47, 40, 0, 8, 46, 13, 0, 8, 45, 11, 0, 7, 44, 0, 12, 50, 17, 3, 12, 49, 15, 1, 11, 48, 1, 16, 36, 3, 0, 16, 35, 1, 0, 41, 8, 2, 2, 40, 7, 2, 2, 39, 5, 0, 45, 12, 0, 6, 44, 11, 0, 6, 43, 9, 0, 49, 42, 0, 10]

cp's OEIS Frontend

A117831 Let S_n be the infinite sequence formed by starting with n and repeatedly reversing the digits and adding 4 to get the next term. Sequence gives number of steps for S_n to reach a cycle, or -1 if no cycle is ever reached.

Table of values

List of values

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

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

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