A299997 - cp's OEIS frontend

A299997 Lexicographic first sequence of positive integers such that a(n)*a(n+1) has a digit 7, and no term occurs twice.

n	a(n)
1	1
2	7
3	10
4	17
5	11
6	16
7	36
8	2
9	35
10	5
11	14
12	27
13	21
14	13
15	6
16	12
17	23
18	9
19	3
20	19
21	4
22	18
23	15
24	25
25	28
26	24
27	30
28	26
29	22
30	8
31	34
32	50
33	54
34	31
35	37
36	20
37	38
38	44
39	29
40	33
41	39
42	43
43	32
44	46
45	45
46	55
47	65
48	42
49	41
50	47
51	51
52	53
53	49
54	56
55	62
56	48
57	57
58	61
59	52
60	63
61	59
62	64
63	58
64	72
65	66
66	83
67	69
68	40
69	68
70	70
71	71
72	67
73	81
74	75
75	73
76	79
77	60
78	95
79	74
80	78
81	86
82	82
83	85
84	84
85	80
86	88
87	77
88	91
89	87

[1, 7, 10, 17, 11, 16, 36, 2, 35, 5, 14, 27, 21, 13, 6, 12, 23, 9, 3, 19, 4, 18, 15, 25, 28, 24, 30, 26, 22, 8, 34, 50, 54, 31, 37, 20, 38, 44, 29, 33, 39, 43, 32, 46, 45, 55, 65, 42, 41, 47, 51, 53, 49, 56, 62, 48, 57, 61, 52, 63, 59, 64, 58, 72, 66, 83, 69, 40, 68, 70, 71, 67, 81, 75, 73, 79, 60, 95, 74, 78, 86, 82, 85, 84, 80, 88, 77, 91, 87]

cp's OEIS Frontend

A299997 Lexicographic first sequence of positive integers such that a(n)*a(n+1) has a digit 7, and no term occurs twice.

Table of values

List of values

n	a(n)
1	1
2	7
3	10
4	17
5	11
6	16
7	36
8	2
9	35
10	5
11	14
12	27
13	21
14	13
15	6
16	12
17	23
18	9
19	3
20	19
21	4
22	18
23	15
24	25
25	28
26	24
27	30
28	26
29	22
30	8
31	34
32	50
33	54
34	31
35	37
36	20
37	38
38	44
39	29
40	33
41	39
42	43
43	32
44	46
45	45
46	55
47	65
48	42
49	41
50	47
51	51
52	53
53	49
54	56
55	62
56	48
57	57
58	61
59	52
60	63
61	59
62	64
63	58
64	72
65	66
66	83
67	69
68	40
69	68
70	70
71	71
72	67
73	81
74	75
75	73
76	79
77	60
78	95
79	74
80	78
81	86
82	82
83	85
84	84
85	80
86	88
87	77
88	91
89	87

n	a(n)
1	1
2	7
3	10
4	17
5	11
6	16
7	36
8	2
9	35
10	5
11	14
12	27
13	21
14	13
15	6
16	12
17	23
18	9
19	3
20	19
21	4
22	18
23	15
24	25
25	28
26	24
27	30
28	26
29	22
30	8
31	34
32	50
33	54
34	31
35	37
36	20
37	38
38	44
39	29
40	33
41	39
42	43
43	32
44	46
45	45
46	55
47	65
48	42
49	41
50	47
51	51
52	53
53	49
54	56
55	62
56	48
57	57
58	61
59	52
60	63
61	59
62	64
63	58
64	72
65	66
66	83
67	69
68	40
69	68
70	70
71	71
72	67
73	81
74	75
75	73
76	79
77	60
78	95
79	74
80	78
81	86
82	82
83	85
84	84
85	80
86	88
87	77
88	91
89	87

n	a(n)
1	1
2	7
3	10
4	17
5	11
6	16
7	36
8	2
9	35
10	5
11	14
12	27
13	21
14	13
15	6
16	12
17	23
18	9
19	3
20	19
21	4
22	18
23	15
24	25
25	28
26	24
27	30
28	26
29	22
30	8
31	34
32	50
33	54
34	31
35	37
36	20
37	38
38	44
39	29
40	33
41	39
42	43
43	32
44	46
45	45
46	55
47	65
48	42
49	41
50	47
51	51
52	53
53	49
54	56
55	62
56	48
57	57
58	61
59	52
60	63
61	59
62	64
63	58
64	72
65	66
66	83
67	69
68	40
69	68
70	70
71	71
72	67
73	81
74	75
75	73
76	79
77	60
78	95
79	74
80	78
81	86
82	82
83	85
84	84
85	80
86	88
87	77
88	91
89	87