A274647 - cp's OEIS frontend

A274647 A variation on Recamán's sequence (A005132): to get a(n), we first try to subtract n from a(n-1): a(n) = a(n-1)-n if positive and not already in the sequence; if not then we try to add n: a(n) = a(n-1)+n if not already in the sequence; if this fails we try to subtract 2n from a(n-1), or to add 2n to a(n-1), or to subtract 3n, or to add 3n, etc., until one of these produces a positive number not already in the sequence.

n	a(n)
0	0
1	1
2	3
3	6
4	2
5	7
6	13
7	20
8	12
9	21
10	11
11	22
12	10
13	23
14	9
15	24
16	8
17	25
18	43
19	62
20	42
21	63
22	41
23	18
24	66
25	91
26	65
27	38
28	94
29	123
30	93
31	124
32	92
33	59
34	127
35	162
36	126
37	89
38	51
39	90
40	50
41	132
42	174
43	131
44	87
45	177
46	223
47	176
48	128
49	79
50	29
51	80
52	28
53	81
54	27
55	82
56	26
57	83
58	141
59	200
60	140
61	201
62	139

[0, 1, 3, 6, 2, 7, 13, 20, 12, 21, 11, 22, 10, 23, 9, 24, 8, 25, 43, 62, 42, 63, 41, 18, 66, 91, 65, 38, 94, 123, 93, 124, 92, 59, 127, 162, 126, 89, 51, 90, 50, 132, 174, 131, 87, 177, 223, 176, 128, 79, 29, 80, 28, 81, 27, 82, 26, 83, 141, 200, 140, 201, 139]

cp's OEIS Frontend

Table of values

List of values

n	a(n)
0	0
1	1
2	3
3	6
4	2
5	7
6	13
7	20
8	12
9	21
10	11
11	22
12	10
13	23
14	9
15	24
16	8
17	25
18	43
19	62
20	42
21	63
22	41
23	18
24	66
25	91
26	65
27	38
28	94
29	123
30	93
31	124
32	92
33	59
34	127
35	162
36	126
37	89
38	51
39	90
40	50
41	132
42	174
43	131
44	87
45	177
46	223
47	176
48	128
49	79
50	29
51	80
52	28
53	81
54	27
55	82
56	26
57	83
58	141
59	200
60	140
61	201
62	139

n	a(n)
0	0
1	1
2	3
3	6
4	2
5	7
6	13
7	20
8	12
9	21
10	11
11	22
12	10
13	23
14	9
15	24
16	8
17	25
18	43
19	62
20	42
21	63
22	41
23	18
24	66
25	91
26	65
27	38
28	94
29	123
30	93
31	124
32	92
33	59
34	127
35	162
36	126
37	89
38	51
39	90
40	50
41	132
42	174
43	131
44	87
45	177
46	223
47	176
48	128
49	79
50	29
51	80
52	28
53	81
54	27
55	82
56	26
57	83
58	141
59	200
60	140
61	201
62	139

n	a(n)
0	0
1	1
2	3
3	6
4	2
5	7
6	13
7	20
8	12
9	21
10	11
11	22
12	10
13	23
14	9
15	24
16	8
17	25
18	43
19	62
20	42
21	63
22	41
23	18
24	66
25	91
26	65
27	38
28	94
29	123
30	93
31	124
32	92
33	59
34	127
35	162
36	126
37	89
38	51
39	90
40	50
41	132
42	174
43	131
44	87
45	177
46	223
47	176
48	128
49	79
50	29
51	80
52	28
53	81
54	27
55	82
56	26
57	83
58	141
59	200
60	140
61	201
62	139