A365159 - cp's OEIS frontend

A365159 a(n)=n for n<=3, and thereafter, a(n) is the number of locations 1..n-1 which cannot be reached starting from i=n-1, where jumps from location i to i +- a(i) are permitted (within 1..n-1). See example.

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

[1, 2, 3, 2, 2, 3, 4, 4, 3, 6, 4, 6, 8, 5, 9, 10, 11, 12, 13, 13, 11, 11, 13, 13, 15, 15, 16, 17, 18, 19, 20, 20, 21, 22, 23, 24, 25, 26, 26, 18, 26, 29, 20, 23, 24, 25, 26, 27, 28, 29, 29, 28, 31, 29, 28, 29, 30, 31, 32, 33, 34, 34, 38, 27, 39, 40, 41, 42, 42]

cp's OEIS Frontend

A365159 a(n)=n for n<=3, and thereafter, a(n) is the number of locations 1..n-1 which cannot be reached starting from i=n-1, where jumps from location i to i +- a(i) are permitted (within 1..n-1). See example.

Table of values

List of values

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

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

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