A132673 - cp's OEIS frontend

A132673 a(1)=1, a(n) = 9*a(n-1) if the minimal positive integer number not yet in the sequence is greater than a(n-1), else a(n) = a(n-1) - 1.

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

[1, 9, 8, 7, 6, 5, 4, 3, 2, 18, 17, 16, 15, 14, 13, 12, 11, 10, 90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 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, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37]

cp's OEIS Frontend

A132673 a(1)=1, a(n) = 9*a(n-1) if the minimal positive integer number 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	9
3	8
4	7
5	6
6	5
7	4
8	3
9	2
10	18
11	17
12	16
13	15
14	14
15	13
16	12
17	11
18	10
19	90
20	89
21	88
22	87
23	86
24	85
25	84
26	83
27	82
28	81
29	80
30	79
31	78
32	77
33	76
34	75
35	74
36	73
37	72
38	71
39	70
40	69
41	68
42	67
43	66
44	65
45	64
46	63
47	62
48	61
49	60
50	59
51	58
52	57
53	56
54	55
55	54
56	53
57	52
58	51
59	50
60	49
61	48
62	47
63	46
64	45
65	44
66	43
67	42
68	41
69	40
70	39
71	38
72	37

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

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