A226996 - cp's OEIS frontend

A226996 Number of lattice paths from (0,0) to (n,n) consisting of steps U=(1,1), H=(1,0) and S=(0,1) such that the first step leaving and the last step joining the diagonal (if any) is an H step.

n	a(n)
0	1
1	1
2	2
3	10
4	59
5	339
6	1908
7	10660
8	59493
9	332469
10	1861910
11	10451086
12	58793535
13	331434215
14	1871929768
15	10590886536
16	60014622089
17	340566437545
18	1935134951402
19	11008701669202
20	62694973984771
21	357406440776891
22	2039344466594972
23	11646264778160300
24	66561506740727149

[1, 1, 2, 10, 59, 339, 1908, 10660, 59493, 332469, 1861910, 10451086, 58793535, 331434215, 1871929768, 10590886536, 60014622089, 340566437545, 1935134951402, 11008701669202, 62694973984771, 357406440776891, 2039344466594972, 11646264778160300, 66561506740727149]

cp's OEIS Frontend

A226996 Number of lattice paths from (0,0) to (n,n) consisting of steps U=(1,1), H=(1,0) and S=(0,1) such that the first step leaving and the last step joining the diagonal (if any) is an H step.

Table of values

List of values