A326825 - cp's OEIS frontend

A326825 a(n) is the number of iterations needed to reach 1 or 5 starting at n and using the map k -> (k/2 if k is even, otherwise k + (smallest triangular number > k)). Set a(n) = -1 if the trajectory never reaches 1 or 5.

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

[0, 1, 6, 2, 0, 7, 7, 3, 5, 1, 12, 8, 10, 8, 8, 4, 6, 6, 4, 2, 15, 13, 58, 9, 56, 11, 52, 9, 36, 9, 15, 5, 28, 7, 13, 7, 20, 5, 18, 3, 18, 16, 16, 14, 59, 59, 59, 10, 14, 57, 57, 12, 55, 53, 51, 10, 22, 37, 55, 10, 24, 16, 22, 6, 35, 29, 14, 8, 27, 14, 12, 8, 10, 21, 23, 6, 27, 19]

cp's OEIS Frontend

A326825 a(n) is the number of iterations needed to reach 1 or 5 starting at n and using the map k -> (k/2 if k is even, otherwise k + (smallest triangular number > k)). Set a(n) = -1 if the trajectory never reaches 1 or 5.

Table of values

List of values

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

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

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