A197654 - cp's OEIS frontend

A197654 Triangle by rows T(n,k), showing the number of meanders with length 5(n+1) and containing 5(k+1) L's and 5(n-k) R's, where L's and R's denote arcs of equal length and a central angle of 72 degrees which are positively or negatively oriented.

n	a(n)
0	1
1	5
2	1
3	31
4	62
5	1
6	121
7	1215
8	363
9	1
10	341
11	13504
12	20256
13	1364
14	1
15	781
16	96875
17	500000
18	193750
19	3905
20	1
21	1555
22	501066
23	7321875
24	9762500
25	1252665
26	9330
27	1
28	2801
29	2033647
30	72656661
31	262609375
32	121094435
33	6100941
34	19607
35	1

[1, 5, 1, 31, 62, 1, 121, 1215, 363, 1, 341, 13504, 20256, 1364, 1, 781, 96875, 500000, 193750, 3905, 1, 1555, 501066, 7321875, 9762500, 1252665, 9330, 1, 2801, 2033647, 72656661, 262609375, 121094435, 6100941, 19607, 1]

cp's OEIS Frontend

A197654 Triangle by rows T(n,k), showing the number of meanders with length 5(n+1) and containing 5(k+1) L's and 5(n-k) R's, where L's and R's denote arcs of equal length and a central angle of 72 degrees which are positively or negatively oriented.

Table of values

List of values