A272727 - cp's OEIS frontend

A272727 a(0)=0; thereafter a(n+1) is the number of coincidences between the sequence so far (a(0), ..., a(n)) and its reverse (a(n), ..., a(0)).

n	a(n)
0	0
1	1
2	0
3	3
4	0
5	3
6	0
7	5
8	0
9	7
10	0
11	7
12	0
13	7
14	0
15	9
16	0
17	9
18	0
19	11
20	0
21	13
22	0
23	15
24	0
25	15
26	0
27	15
28	0
29	15
30	0
31	17
32	0
33	19
34	0
35	19
36	0
37	19
38	0
39	21
40	0
41	21
42	0
43	23
44	0
45	23
46	0
47	25
48	0
49	27
50	0
51	29
52	0
53	31
54	0
55	31
56	0
57	31
58	0
59	31
60	0
61	31
62	0
63	33
64	0
65	33
66	0
67	35
68	0
69	37
70	0
71	39
72	0
73	39
74	0
75	39
76	0
77	39
78	0
79	41
80	0
81	43

[0, 1, 0, 3, 0, 3, 0, 5, 0, 7, 0, 7, 0, 7, 0, 9, 0, 9, 0, 11, 0, 13, 0, 15, 0, 15, 0, 15, 0, 15, 0, 17, 0, 19, 0, 19, 0, 19, 0, 21, 0, 21, 0, 23, 0, 23, 0, 25, 0, 27, 0, 29, 0, 31, 0, 31, 0, 31, 0, 31, 0, 31, 0, 33, 0, 33, 0, 35, 0, 37, 0, 39, 0, 39, 0, 39, 0, 39, 0, 41, 0, 43]

cp's OEIS Frontend

A272727 a(0)=0; thereafter a(n+1) is the number of coincidences between the sequence so far (a(0), ..., a(n)) and its reverse (a(n), ..., a(0)).

Table of values

List of values

n	a(n)
0	0
1	1
2	0
3	3
4	0
5	3
6	0
7	5
8	0
9	7
10	0
11	7
12	0
13	7
14	0
15	9
16	0
17	9
18	0
19	11
20	0
21	13
22	0
23	15
24	0
25	15
26	0
27	15
28	0
29	15
30	0
31	17
32	0
33	19
34	0
35	19
36	0
37	19
38	0
39	21
40	0
41	21
42	0
43	23
44	0
45	23
46	0
47	25
48	0
49	27
50	0
51	29
52	0
53	31
54	0
55	31
56	0
57	31
58	0
59	31
60	0
61	31
62	0
63	33
64	0
65	33
66	0
67	35
68	0
69	37
70	0
71	39
72	0
73	39
74	0
75	39
76	0
77	39
78	0
79	41
80	0
81	43

n	a(n)
0	0
1	1
2	0
3	3
4	0
5	3
6	0
7	5
8	0
9	7
10	0
11	7
12	0
13	7
14	0
15	9
16	0
17	9
18	0
19	11
20	0
21	13
22	0
23	15
24	0
25	15
26	0
27	15
28	0
29	15
30	0
31	17
32	0
33	19
34	0
35	19
36	0
37	19
38	0
39	21
40	0
41	21
42	0
43	23
44	0
45	23
46	0
47	25
48	0
49	27
50	0
51	29
52	0
53	31
54	0
55	31
56	0
57	31
58	0
59	31
60	0
61	31
62	0
63	33
64	0
65	33
66	0
67	35
68	0
69	37
70	0
71	39
72	0
73	39
74	0
75	39
76	0
77	39
78	0
79	41
80	0
81	43

n	a(n)
0	0
1	1
2	0
3	3
4	0
5	3
6	0
7	5
8	0
9	7
10	0
11	7
12	0
13	7
14	0
15	9
16	0
17	9
18	0
19	11
20	0
21	13
22	0
23	15
24	0
25	15
26	0
27	15
28	0
29	15
30	0
31	17
32	0
33	19
34	0
35	19
36	0
37	19
38	0
39	21
40	0
41	21
42	0
43	23
44	0
45	23
46	0
47	25
48	0
49	27
50	0
51	29
52	0
53	31
54	0
55	31
56	0
57	31
58	0
59	31
60	0
61	31
62	0
63	33
64	0
65	33
66	0
67	35
68	0
69	37
70	0
71	39
72	0
73	39
74	0
75	39
76	0
77	39
78	0
79	41
80	0
81	43