A026440 - cp's OEIS frontend

A026440 a(n) = least positive integer > a(n-1) and not a(i)*a(j)-1 for 1 <= i <= j < n, n >= 2, with initial terms 1,4.

n	a(n)
1	1
2	4
3	5
4	6
5	7
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	16
14	17
15	18
16	20
17	21
18	22
19	25
20	26
21	28
22	30
23	32
24	33
25	36
26	37
27	38
28	40
29	42
30	45
31	46
32	50
33	52
34	56
35	57
36	58
37	60
38	61
39	66
40	68
41	70
42	72
43	73
44	74
45	75
46	78
47	81
48	82
49	85
50	86
51	88
52	91
53	92
54	93
55	94
56	96
57	100
58	102
59	105
60	106

[1, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, 17, 18, 20, 21, 22, 25, 26, 28, 30, 32, 33, 36, 37, 38, 40, 42, 45, 46, 50, 52, 56, 57, 58, 60, 61, 66, 68, 70, 72, 73, 74, 75, 78, 81, 82, 85, 86, 88, 91, 92, 93, 94, 96, 100, 102, 105, 106]

cp's OEIS Frontend

A026440 a(n) = least positive integer > a(n-1) and not a(i)*a(j)-1 for 1 <= i <= j < n, n >= 2, with initial terms 1,4.

Table of values

List of values

n	a(n)
1	1
2	4
3	5
4	6
5	7
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	16
14	17
15	18
16	20
17	21
18	22
19	25
20	26
21	28
22	30
23	32
24	33
25	36
26	37
27	38
28	40
29	42
30	45
31	46
32	50
33	52
34	56
35	57
36	58
37	60
38	61
39	66
40	68
41	70
42	72
43	73
44	74
45	75
46	78
47	81
48	82
49	85
50	86
51	88
52	91
53	92
54	93
55	94
56	96
57	100
58	102
59	105
60	106

n	a(n)
1	1
2	4
3	5
4	6
5	7
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	16
14	17
15	18
16	20
17	21
18	22
19	25
20	26
21	28
22	30
23	32
24	33
25	36
26	37
27	38
28	40
29	42
30	45
31	46
32	50
33	52
34	56
35	57
36	58
37	60
38	61
39	66
40	68
41	70
42	72
43	73
44	74
45	75
46	78
47	81
48	82
49	85
50	86
51	88
52	91
53	92
54	93
55	94
56	96
57	100
58	102
59	105
60	106

n	a(n)
1	1
2	4
3	5
4	6
5	7
6	8
7	9
8	10
9	11
10	12
11	13
12	14
13	16
14	17
15	18
16	20
17	21
18	22
19	25
20	26
21	28
22	30
23	32
24	33
25	36
26	37
27	38
28	40
29	42
30	45
31	46
32	50
33	52
34	56
35	57
36	58
37	60
38	61
39	66
40	68
41	70
42	72
43	73
44	74
45	75
46	78
47	81
48	82
49	85
50	86
51	88
52	91
53	92
54	93
55	94
56	96
57	100
58	102
59	105
60	106