A132665 - cp's OEIS frontend

A132665 a(1)=1, a(2)=3, a(n) = a(n-1) + n if the minimal positive integer not yet in the sequencer is greater than a(n-1), else a(n) = a(n-1)-1.

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

[1, 3, 2, 6, 5, 4, 11, 10, 9, 8, 7, 19, 18, 17, 16, 15, 14, 13, 12, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69]

cp's OEIS Frontend

A132665 a(1)=1, a(2)=3, a(n) = a(n-1) + n if the minimal positive integer not yet in the sequencer 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	3
3	2
4	6
5	5
6	4
7	11
8	10
9	9
10	8
11	7
12	19
13	18
14	17
15	16
16	15
17	14
18	13
19	12
20	32
21	31
22	30
23	29
24	28
25	27
26	26
27	25
28	24
29	23
30	22
31	21
32	20
33	53
34	52
35	51
36	50
37	49
38	48
39	47
40	46
41	45
42	44
43	43
44	42
45	41
46	40
47	39
48	38
49	37
50	36
51	35
52	34
53	33
54	87
55	86
56	85
57	84
58	83
59	82
60	81
61	80
62	79
63	78
64	77
65	76
66	75
67	74
68	73
69	72
70	71
71	70
72	69

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

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