A026431 - cp's OEIS frontend

A026431 a(n) = least positive integer > a(n-1) and not a(i)*a(j)-1 for 1<=i with initial terms 1,2.

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	12
10	13
11	14
12	16
13	18
14	20
15	21
16	22
17	24
18	28
19	30
20	32
21	33
22	34
23	36
24	37
25	40
26	42
27	44
28	45
29	46
30	48
31	49
32	50
33	52
34	54
35	56
36	57
37	58
38	60
39	61
40	64
41	66
42	68
43	69
44	70
45	72
46	74
47	75
48	76
49	78
50	80
51	81
52	82
53	84
54	85
55	86
56	88
57	90
58	92
59	93
60	94

[1, 2, 3, 4, 6, 8, 9, 10, 12, 13, 14, 16, 18, 20, 21, 22, 24, 28, 30, 32, 33, 34, 36, 37, 40, 42, 44, 45, 46, 48, 49, 50, 52, 54, 56, 57, 58, 60, 61, 64, 66, 68, 69, 70, 72, 74, 75, 76, 78, 80, 81, 82, 84, 85, 86, 88, 90, 92, 93, 94]

cp's OEIS Frontend

A026431 a(n) = least positive integer > a(n-1) and not a(i)*a(j)-1 for 1<=i with initial terms 1,2.

Table of values

List of values

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	12
10	13
11	14
12	16
13	18
14	20
15	21
16	22
17	24
18	28
19	30
20	32
21	33
22	34
23	36
24	37
25	40
26	42
27	44
28	45
29	46
30	48
31	49
32	50
33	52
34	54
35	56
36	57
37	58
38	60
39	61
40	64
41	66
42	68
43	69
44	70
45	72
46	74
47	75
48	76
49	78
50	80
51	81
52	82
53	84
54	85
55	86
56	88
57	90
58	92
59	93
60	94

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	12
10	13
11	14
12	16
13	18
14	20
15	21
16	22
17	24
18	28
19	30
20	32
21	33
22	34
23	36
24	37
25	40
26	42
27	44
28	45
29	46
30	48
31	49
32	50
33	52
34	54
35	56
36	57
37	58
38	60
39	61
40	64
41	66
42	68
43	69
44	70
45	72
46	74
47	75
48	76
49	78
50	80
51	81
52	82
53	84
54	85
55	86
56	88
57	90
58	92
59	93
60	94

n	a(n)
1	1
2	2
3	3
4	4
5	6
6	8
7	9
8	10
9	12
10	13
11	14
12	16
13	18
14	20
15	21
16	22
17	24
18	28
19	30
20	32
21	33
22	34
23	36
24	37
25	40
26	42
27	44
28	45
29	46
30	48
31	49
32	50
33	52
34	54
35	56
36	57
37	58
38	60
39	61
40	64
41	66
42	68
43	69
44	70
45	72
46	74
47	75
48	76
49	78
50	80
51	81
52	82
53	84
54	85
55	86
56	88
57	90
58	92
59	93
60	94