A132664 - cp's OEIS frontend

A132664 a(1)=1, a(2)=2, a(n) = a(n-1) + n if the minimal positive integer not yet in the sequence is greater than a(n-1), else a(n) = a(n-1) - 1.

n	a(n)
1	1
2	2
3	5
4	4
5	3
6	9
7	8
8	7
9	6
10	16
11	15
12	14
13	13
14	12
15	11
16	10
17	27
18	26
19	25
20	24
21	23
22	22
23	21
24	20
25	19
26	18
27	17
28	45
29	44
30	43
31	42
32	41
33	40
34	39
35	38
36	37
37	36
38	35
39	34
40	33
41	32
42	31
43	30
44	29
45	28
46	74
47	73
48	72
49	71
50	70
51	69
52	68
53	67
54	66
55	65
56	64
57	63
58	62
59	61
60	60
61	59
62	58
63	57
64	56
65	55
66	54
67	53
68	52
69	51
70	50
71	49
72	48

[1, 2, 5, 4, 3, 9, 8, 7, 6, 16, 15, 14, 13, 12, 11, 10, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48]

cp's OEIS Frontend

A132664 a(1)=1, a(2)=2, a(n) = a(n-1) + n if the minimal positive integer not yet in the sequence is greater than a(n-1), else a(n) = a(n-1) - 1.

Table of values

List of values

n	a(n)
1	1
2	2
3	5
4	4
5	3
6	9
7	8
8	7
9	6
10	16
11	15
12	14
13	13
14	12
15	11
16	10
17	27
18	26
19	25
20	24
21	23
22	22
23	21
24	20
25	19
26	18
27	17
28	45
29	44
30	43
31	42
32	41
33	40
34	39
35	38
36	37
37	36
38	35
39	34
40	33
41	32
42	31
43	30
44	29
45	28
46	74
47	73
48	72
49	71
50	70
51	69
52	68
53	67
54	66
55	65
56	64
57	63
58	62
59	61
60	60
61	59
62	58
63	57
64	56
65	55
66	54
67	53
68	52
69	51
70	50
71	49
72	48

n	a(n)
1	1
2	2
3	5
4	4
5	3
6	9
7	8
8	7
9	6
10	16
11	15
12	14
13	13
14	12
15	11
16	10
17	27
18	26
19	25
20	24
21	23
22	22
23	21
24	20
25	19
26	18
27	17
28	45
29	44
30	43
31	42
32	41
33	40
34	39
35	38
36	37
37	36
38	35
39	34
40	33
41	32
42	31
43	30
44	29
45	28
46	74
47	73
48	72
49	71
50	70
51	69
52	68
53	67
54	66
55	65
56	64
57	63
58	62
59	61
60	60
61	59
62	58
63	57
64	56
65	55
66	54
67	53
68	52
69	51
70	50
71	49
72	48

n	a(n)
1	1
2	2
3	5
4	4
5	3
6	9
7	8
8	7
9	6
10	16
11	15
12	14
13	13
14	12
15	11
16	10
17	27
18	26
19	25
20	24
21	23
22	22
23	21
24	20
25	19
26	18
27	17
28	45
29	44
30	43
31	42
32	41
33	40
34	39
35	38
36	37
37	36
38	35
39	34
40	33
41	32
42	31
43	30
44	29
45	28
46	74
47	73
48	72
49	71
50	70
51	69
52	68
53	67
54	66
55	65
56	64
57	63
58	62
59	61
60	60
61	59
62	58
63	57
64	56
65	55
66	54
67	53
68	52
69	51
70	50
71	49
72	48