A025143 - cp's OEIS frontend

A025143 Unique sequence a of 1's and 2's such that a(1) = 2 and r(r(a)) = a != r(a), where for any sequence s, r(s) is the sequence of lengths of runs of same symbols in s; r(a) is sequence A025142.

n	a(n)
1	2
2	1
3	2
4	2
5	1
6	2
7	1
8	1
9	2
10	2
11	1
12	2
13	2
14	1
15	1
16	2
17	1
18	1
19	2
20	1
21	2
22	2
23	1
24	1
25	2
26	1
27	1
28	2
29	2
30	1
31	2
32	1
33	1
34	2
35	1
36	1
37	2
38	2
39	1
40	2
41	2
42	1
43	2
44	1
45	1
46	2
47	1
48	2
49	2
50	1
51	1
52	2
53	1
54	1
55	2
56	1
57	2
58	2
59	1
60	2
61	2
62	1
63	1
64	2
65	1
66	2
67	2
68	1
69	2
70	1
71	1
72	2
73	1
74	1
75	2
76	2
77	1
78	2
79	2
80	1
81	2
82	1
83	1
84	2
85	2
86	1
87	2
88	2
89	1
90	1
91	2
92	1
93	2
94	2
95	1
96	2
97	1
98	1
99	2
100	1
101	1
102	2
103	2
104	1
105	2
106	2
107	1
108	1
109	2
110	1
111	2

[2, 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 2]

cp's OEIS Frontend

A025143 Unique sequence a of 1's and 2's such that a(1) = 2 and r(r(a)) = a != r(a), where for any sequence s, r(s) is the sequence of lengths of runs of same symbols in s; r(a) is sequence A025142.

Table of values

List of values

n	a(n)
1	2
2	1
3	2
4	2
5	1
6	2
7	1
8	1
9	2
10	2
11	1
12	2
13	2
14	1
15	1
16	2
17	1
18	1
19	2
20	1
21	2
22	2
23	1
24	1
25	2
26	1
27	1
28	2
29	2
30	1
31	2
32	1
33	1
34	2
35	1
36	1
37	2
38	2
39	1
40	2
41	2
42	1
43	2
44	1
45	1
46	2
47	1
48	2
49	2
50	1
51	1
52	2
53	1
54	1
55	2
56	1
57	2
58	2
59	1
60	2
61	2
62	1
63	1
64	2
65	1
66	2
67	2
68	1
69	2
70	1
71	1
72	2
73	1
74	1
75	2
76	2
77	1
78	2
79	2
80	1
81	2
82	1
83	1
84	2
85	2
86	1
87	2
88	2
89	1
90	1
91	2
92	1
93	2
94	2
95	1
96	2
97	1
98	1
99	2
100	1
101	1
102	2
103	2
104	1
105	2
106	2
107	1
108	1
109	2
110	1
111	2

n	a(n)
1	2
2	1
3	2
4	2
5	1
6	2
7	1
8	1
9	2
10	2
11	1
12	2
13	2
14	1
15	1
16	2
17	1
18	1
19	2
20	1
21	2
22	2
23	1
24	1
25	2
26	1
27	1
28	2
29	2
30	1
31	2
32	1
33	1
34	2
35	1
36	1
37	2
38	2
39	1
40	2
41	2
42	1
43	2
44	1
45	1
46	2
47	1
48	2
49	2
50	1
51	1
52	2
53	1
54	1
55	2
56	1
57	2
58	2
59	1
60	2
61	2
62	1
63	1
64	2
65	1
66	2
67	2
68	1
69	2
70	1
71	1
72	2
73	1
74	1
75	2
76	2
77	1
78	2
79	2
80	1
81	2
82	1
83	1
84	2
85	2
86	1
87	2
88	2
89	1
90	1
91	2
92	1
93	2
94	2
95	1
96	2
97	1
98	1
99	2
100	1
101	1
102	2
103	2
104	1
105	2
106	2
107	1
108	1
109	2
110	1
111	2

n	a(n)
1	2
2	1
3	2
4	2
5	1
6	2
7	1
8	1
9	2
10	2
11	1
12	2
13	2
14	1
15	1
16	2
17	1
18	1
19	2
20	1
21	2
22	2
23	1
24	1
25	2
26	1
27	1
28	2
29	2
30	1
31	2
32	1
33	1
34	2
35	1
36	1
37	2
38	2
39	1
40	2
41	2
42	1
43	2
44	1
45	1
46	2
47	1
48	2
49	2
50	1
51	1
52	2
53	1
54	1
55	2
56	1
57	2
58	2
59	1
60	2
61	2
62	1
63	1
64	2
65	1
66	2
67	2
68	1
69	2
70	1
71	1
72	2
73	1
74	1
75	2
76	2
77	1
78	2
79	2
80	1
81	2
82	1
83	1
84	2
85	2
86	1
87	2
88	2
89	1
90	1
91	2
92	1
93	2
94	2
95	1
96	2
97	1
98	1
99	2
100	1
101	1
102	2
103	2
104	1
105	2
106	2
107	1
108	1
109	2
110	1
111	2