A026325 - cp's OEIS frontend

A026325 Number of paths in the plane x >= 0 and y >= -2, from (0,0) to (n,0), and consisting of steps U = (1,1), D = (1,-1) and H = (1,0).

n	a(n)
0	1
1	1
2	3
3	7
4	19
5	51
6	140
7	386
8	1071
9	2983
10	8338
11	23376
12	65715
13	185199
14	523134
15	1480872
16	4200411
17	11936619
18	33981063
19	96897759
20	276739029
21	791532973
22	2267119660
23	6502108902
24	18671460905
25	53680763201
26	154507444731
27	445190930863
28	1284064525987

[1, 1, 3, 7, 19, 51, 140, 386, 1071, 2983, 8338, 23376, 65715, 185199, 523134, 1480872, 4200411, 11936619, 33981063, 96897759, 276739029, 791532973, 2267119660, 6502108902, 18671460905, 53680763201, 154507444731, 445190930863, 1284064525987]

cp's OEIS Frontend

A026325 Number of paths in the plane x >= 0 and y >= -2, from (0,0) to (n,0), and consisting of steps U = (1,1), D = (1,-1) and H = (1,0).

Table of values

List of values