A327723 - cp's OEIS frontend

A327723 a(1) = 0. For n > 1, a(n) is the smallest positive integer k not already in the sequence such that the least significant digit of k equals the most significant digit of a(n-1).

n	a(n)
1	0
2	10
3	1
4	11
5	21
6	2
7	12
8	31
9	3
10	13
11	41
12	4
13	14
14	51
15	5
16	15
17	61
18	6
19	16
20	71
21	7
22	17
23	81
24	8
25	18
26	91
27	9
28	19
29	101
30	111
31	121
32	131
33	141
34	151
35	161
36	171
37	181
38	191
39	201
40	22
41	32
42	23
43	42
44	24
45	52
46	25
47	62
48	26
49	72
50	27
51	82
52	28
53	92
54	29
55	102
56	211
57	112
58	221
59	122
60	231
61	132
62	241
63	142

[0, 10, 1, 11, 21, 2, 12, 31, 3, 13, 41, 4, 14, 51, 5, 15, 61, 6, 16, 71, 7, 17, 81, 8, 18, 91, 9, 19, 101, 111, 121, 131, 141, 151, 161, 171, 181, 191, 201, 22, 32, 23, 42, 24, 52, 25, 62, 26, 72, 27, 82, 28, 92, 29, 102, 211, 112, 221, 122, 231, 132, 241, 142]

cp's OEIS Frontend

A327723 a(1) = 0. For n > 1, a(n) is the smallest positive integer k not already in the sequence such that the least significant digit of k equals the most significant digit of a(n-1).

Table of values

List of values

n	a(n)
1	0
2	10
3	1
4	11
5	21
6	2
7	12
8	31
9	3
10	13
11	41
12	4
13	14
14	51
15	5
16	15
17	61
18	6
19	16
20	71
21	7
22	17
23	81
24	8
25	18
26	91
27	9
28	19
29	101
30	111
31	121
32	131
33	141
34	151
35	161
36	171
37	181
38	191
39	201
40	22
41	32
42	23
43	42
44	24
45	52
46	25
47	62
48	26
49	72
50	27
51	82
52	28
53	92
54	29
55	102
56	211
57	112
58	221
59	122
60	231
61	132
62	241
63	142

n	a(n)
1	0
2	10
3	1
4	11
5	21
6	2
7	12
8	31
9	3
10	13
11	41
12	4
13	14
14	51
15	5
16	15
17	61
18	6
19	16
20	71
21	7
22	17
23	81
24	8
25	18
26	91
27	9
28	19
29	101
30	111
31	121
32	131
33	141
34	151
35	161
36	171
37	181
38	191
39	201
40	22
41	32
42	23
43	42
44	24
45	52
46	25
47	62
48	26
49	72
50	27
51	82
52	28
53	92
54	29
55	102
56	211
57	112
58	221
59	122
60	231
61	132
62	241
63	142

n	a(n)
1	0
2	10
3	1
4	11
5	21
6	2
7	12
8	31
9	3
10	13
11	41
12	4
13	14
14	51
15	5
16	15
17	61
18	6
19	16
20	71
21	7
22	17
23	81
24	8
25	18
26	91
27	9
28	19
29	101
30	111
31	121
32	131
33	141
34	151
35	161
36	171
37	181
38	191
39	201
40	22
41	32
42	23
43	42
44	24
45	52
46	25
47	62
48	26
49	72
50	27
51	82
52	28
53	92
54	29
55	102
56	211
57	112
58	221
59	122
60	231
61	132
62	241
63	142