A304237 - cp's OEIS frontend

A304237 a(n) is the smallest positive integer not yet in the sequence that is obtained when the first and last digits of a(n-1) are exchanged and used in a(n) in the exchanged order (but not necessarily adjacent); a(1)=10.

n	a(n)
1	10
2	101
3	11
4	110
5	201
6	12
7	21
8	102
9	121
10	111
11	112
12	210
13	202
14	22
15	122
16	211
17	120
18	301
19	13
20	31
21	103
22	131
23	113
24	231
25	123
26	310
27	203
28	32
29	23
30	132
31	212
32	220
33	302
34	213
35	232
36	221
37	124
38	41
39	14
40	141
41	114
42	241
43	125
44	51
45	15
46	151
47	115
48	251
49	126
50	61
51	16
52	161
53	116
54	261
55	127
56	71
57	17
58	171
59	117
60	271
61	128
62	81
63	18
64	181
65	118

[10, 101, 11, 110, 201, 12, 21, 102, 121, 111, 112, 210, 202, 22, 122, 211, 120, 301, 13, 31, 103, 131, 113, 231, 123, 310, 203, 32, 23, 132, 212, 220, 302, 213, 232, 221, 124, 41, 14, 141, 114, 241, 125, 51, 15, 151, 115, 251, 126, 61, 16, 161, 116, 261, 127, 71, 17, 171, 117, 271, 128, 81, 18, 181, 118]

cp's OEIS Frontend

A304237 a(n) is the smallest positive integer not yet in the sequence that is obtained when the first and last digits of a(n-1) are exchanged and used in a(n) in the exchanged order (but not necessarily adjacent); a(1)=10.

Table of values

List of values

n	a(n)
1	10
2	101
3	11
4	110
5	201
6	12
7	21
8	102
9	121
10	111
11	112
12	210
13	202
14	22
15	122
16	211
17	120
18	301
19	13
20	31
21	103
22	131
23	113
24	231
25	123
26	310
27	203
28	32
29	23
30	132
31	212
32	220
33	302
34	213
35	232
36	221
37	124
38	41
39	14
40	141
41	114
42	241
43	125
44	51
45	15
46	151
47	115
48	251
49	126
50	61
51	16
52	161
53	116
54	261
55	127
56	71
57	17
58	171
59	117
60	271
61	128
62	81
63	18
64	181
65	118

n	a(n)
1	10
2	101
3	11
4	110
5	201
6	12
7	21
8	102
9	121
10	111
11	112
12	210
13	202
14	22
15	122
16	211
17	120
18	301
19	13
20	31
21	103
22	131
23	113
24	231
25	123
26	310
27	203
28	32
29	23
30	132
31	212
32	220
33	302
34	213
35	232
36	221
37	124
38	41
39	14
40	141
41	114
42	241
43	125
44	51
45	15
46	151
47	115
48	251
49	126
50	61
51	16
52	161
53	116
54	261
55	127
56	71
57	17
58	171
59	117
60	271
61	128
62	81
63	18
64	181
65	118

n	a(n)
1	10
2	101
3	11
4	110
5	201
6	12
7	21
8	102
9	121
10	111
11	112
12	210
13	202
14	22
15	122
16	211
17	120
18	301
19	13
20	31
21	103
22	131
23	113
24	231
25	123
26	310
27	203
28	32
29	23
30	132
31	212
32	220
33	302
34	213
35	232
36	221
37	124
38	41
39	14
40	141
41	114
42	241
43	125
44	51
45	15
46	151
47	115
48	251
49	126
50	61
51	16
52	161
53	116
54	261
55	127
56	71
57	17
58	171
59	117
60	271
61	128
62	81
63	18
64	181
65	118