A335923 - cp's OEIS frontend

A335923 A variation on Recamán's sequence (A005132): a(0) = 0, a(n) = a(n-1) - n if a(n) is nonnegative and not already in the sequence, otherwise a(n) = a(n-1) + ceiling(n/2).

n	a(n)
0	0
1	1
2	2
3	4
4	6
5	9
6	3
7	7
8	11
9	16
10	21
11	10
12	16
13	23
14	30
15	15
16	23
17	32
18	14
19	24
20	34
21	13
22	24
23	36
24	12
25	25
26	38
27	52
28	66
29	37
30	52
31	68
32	84
33	51
34	17
35	35
36	53
37	72
38	91
39	111
40	71
41	92
42	50
43	72
44	28
45	51
46	5
47	29
48	53
49	78
50	103
51	129
52	77
53	104
54	131
55	76
56	20
57	49
58	78
59	19
60	49
61	80
62	18
63	50
64	82
65	115

[0, 1, 2, 4, 6, 9, 3, 7, 11, 16, 21, 10, 16, 23, 30, 15, 23, 32, 14, 24, 34, 13, 24, 36, 12, 25, 38, 52, 66, 37, 52, 68, 84, 51, 17, 35, 53, 72, 91, 111, 71, 92, 50, 72, 28, 51, 5, 29, 53, 78, 103, 129, 77, 104, 131, 76, 20, 49, 78, 19, 49, 80, 18, 50, 82, 115]

cp's OEIS Frontend

A335923 A variation on Recamán's sequence (A005132): a(0) = 0, a(n) = a(n-1) - n if a(n) is nonnegative and not already in the sequence, otherwise a(n) = a(n-1) + ceiling(n/2).

Table of values

List of values

n	a(n)
0	0
1	1
2	2
3	4
4	6
5	9
6	3
7	7
8	11
9	16
10	21
11	10
12	16
13	23
14	30
15	15
16	23
17	32
18	14
19	24
20	34
21	13
22	24
23	36
24	12
25	25
26	38
27	52
28	66
29	37
30	52
31	68
32	84
33	51
34	17
35	35
36	53
37	72
38	91
39	111
40	71
41	92
42	50
43	72
44	28
45	51
46	5
47	29
48	53
49	78
50	103
51	129
52	77
53	104
54	131
55	76
56	20
57	49
58	78
59	19
60	49
61	80
62	18
63	50
64	82
65	115

n	a(n)
0	0
1	1
2	2
3	4
4	6
5	9
6	3
7	7
8	11
9	16
10	21
11	10
12	16
13	23
14	30
15	15
16	23
17	32
18	14
19	24
20	34
21	13
22	24
23	36
24	12
25	25
26	38
27	52
28	66
29	37
30	52
31	68
32	84
33	51
34	17
35	35
36	53
37	72
38	91
39	111
40	71
41	92
42	50
43	72
44	28
45	51
46	5
47	29
48	53
49	78
50	103
51	129
52	77
53	104
54	131
55	76
56	20
57	49
58	78
59	19
60	49
61	80
62	18
63	50
64	82
65	115

n	a(n)
0	0
1	1
2	2
3	4
4	6
5	9
6	3
7	7
8	11
9	16
10	21
11	10
12	16
13	23
14	30
15	15
16	23
17	32
18	14
19	24
20	34
21	13
22	24
23	36
24	12
25	25
26	38
27	52
28	66
29	37
30	52
31	68
32	84
33	51
34	17
35	35
36	53
37	72
38	91
39	111
40	71
41	92
42	50
43	72
44	28
45	51
46	5
47	29
48	53
49	78
50	103
51	129
52	77
53	104
54	131
55	76
56	20
57	49
58	78
59	19
60	49
61	80
62	18
63	50
64	82
65	115