A089387 - cp's OEIS frontend

A089387 Number of Schroeder paths of semilength n (i.e., lattice paths from (0,0) to (2n,0), with steps H=(2,0), U=(1,1) and D(1,-1) and not going below the x-axis) with no UD, UHD, UHHD, UHHHD, ... starting at level zero.

n	a(n)
0	1
1	1
2	2
3	8
4	36
5	164
6	764
7	3652
8	17852
9	88868
10	449004
11	2296692
12	11870316
13	61897140
14	325239036
15	1720415268
16	9154052700
17	48961321604
18	263092909004
19	1419630359572
20	7689097400588
21	41788586179988
22	227819374037340
23	1245545102522948

[1, 1, 2, 8, 36, 164, 764, 3652, 17852, 88868, 449004, 2296692, 11870316, 61897140, 325239036, 1720415268, 9154052700, 48961321604, 263092909004, 1419630359572, 7689097400588, 41788586179988, 227819374037340, 1245545102522948]

cp's OEIS Frontend

A089387 Number of Schroeder paths of semilength n (i.e., lattice paths from (0,0) to (2n,0), with steps H=(2,0), U=(1,1) and D(1,-1) and not going below the x-axis) with no UD, UHD, UHHD, UHHHD, ... starting at level zero.

Table of values

List of values