A104156 - cp's OEIS frontend

A104156 a(1)=a(2)=0, a(n) = abs(2*a(n-1) - a(n-2)) - 1.

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

[0, 0, -1, 1, 2, 2, 1, -1, 2, 4, 5, 5, 4, 2, -1, 3, 6, 8, 9, 9, 8, 6, 3, -1, 4, 8, 11, 13, 14, 14, 13, 11, 8, 4, -1, 5, 10, 14, 17, 19, 20, 20, 19, 17, 14, 10, 5, -1, 6, 12, 17, 21, 24, 26, 27, 27, 26, 24, 21, 17, 12, 6, -1, 7, 14, 20, 25, 29, 32, 34, 35, 35, 34, 32, 29, 25, 20, 14, 7, -1, 8, 16, 23, 29, 34, 38, 41, 43, 44, 44, 43, 41, 38, 34, 29, 23]

cp's OEIS Frontend

A104156 a(1)=a(2)=0, a(n) = abs(2*a(n-1) - a(n-2)) - 1.

Table of values

List of values

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

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

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