A110335 - cp's OEIS frontend

A110335 Number of valleys (i.e., (1,-1) followed by (1,1)) at level zero in all peakless Motzkin paths of length n+6 (can be easily translated into RNA secondary structure terminology).

n	a(n)
0	1
1	4
2	12
3	34
4	92
5	242
6	627
7	1608
8	4096
9	10388
10	26269
11	66304
12	167161
13	421162
14	1060816
15	2671908
16	6730941
17	16961430
18	42758695
19	107843080
20	272136858
21	687106696
22	1735849310
23	4387895300
24	11098372185
25	28088028612
26	71128006458
27	180224822694

[1, 4, 12, 34, 92, 242, 627, 1608, 4096, 10388, 26269, 66304, 167161, 421162, 1060816, 2671908, 6730941, 16961430, 42758695, 107843080, 272136858, 687106696, 1735849310, 4387895300, 11098372185, 28088028612, 71128006458, 180224822694]

cp's OEIS Frontend

A110335 Number of valleys (i.e., (1,-1) followed by (1,1)) at level zero in all peakless Motzkin paths of length n+6 (can be easily translated into RNA secondary structure terminology).

Table of values

List of values