A240807 - cp's OEIS frontend

A240807 a(0)=a(1)=-1, a(2)=2; thereafter a(n) = a(n-1-a(n-1))+a(n-2-a(n-2)) unless a(n-1) <= n-1 or a(n-2) <= n-2 in which case the sequence terminates.

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

[-1, -1, 2, 1, 1, 3, 3, 3, 2, 4, 6, 4, 4, 5, 4, 8, 9, 6, 7, 8, 8, 8, 9, 10, 10, 9, 13, 14, 10, 12, 13, 12, 14, 15, 14, 15, 16, 16, 16, 17, 18, 18, 19, 20, 20, 20, 19, 23, 24, 20, 22, 22, 22, 25, 23, 22, 27, 27, 25, 28, 27, 27, 29, 29, 29, 29, 31, 31, 31, 32, 32, 32, 33, 34, 34, 35, 36, 36, 36, 37, 38, 38, 39, 40, 40, 40, 40, 39, 43, 44, 40, 42, 42, 42]

cp's OEIS Frontend

A240807 a(0)=a(1)=-1, a(2)=2; thereafter a(n) = a(n-1-a(n-1))+a(n-2-a(n-2)) unless a(n-1) <= n-1 or a(n-2) <= n-2 in which case the sequence terminates.

Table of values

List of values

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

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

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