A087571 - OEIS

A087571 as a simple table

n	a(n)
1	0
2	2
3	3
4	43
5	5
6	0
7	7
8	0
9	0
10	109
11	11
12	0
13	13
14	0
15	0
16	0
17	17
18	0
19	19
20	0
21	0
22	2221
23	23
24	2423
25	25242322212019181716151413
26	0
27	2726252423
28	0
29	29
30	0
31	31
32	0
33	0
34	3433
35	0
36	0
37	37
38	0
39	0
40	0
41	41
42	4241
43	43
44	0
45	0
46	4645444342414039
47	47
48	4847464544434241
49	0
50	0
51	5150494847

[0,2,3,43,5,0,7,0,0,109,11,0,13,0,0,0,17,0,19,0,0, 2221,23,2423,25242322212019181716151413,0, 2726252423,0,29,0,31,0,0,3433,0,0,37,0,0,0,41, 4241,43,0,0,4645444342414039,47,4847464544434241, 0,0,5150494847]