A151341 - cp's OEIS frontend

A151341 Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of 2 n steps taken from {(-1, -1), (-1, 0), (-1, 1), (1, 0)}.

n	a(n)
0	1
1	1
2	4
3	20
4	126
5	882
6	6732
7	54483
8	461890
9	4059770
10	36749648
11	340841228
12	3226474132
13	31079221500
14	303907314960
15	3010947401340
16	30176604541890
17	305544118531410
18	3122029001183400
19	32162924697555960
20	333798776316127980
21	3487606641543204180
22	36662847052669011720
23	387575171486963664750

[1, 1, 4, 20, 126, 882, 6732, 54483, 461890, 4059770, 36749648, 340841228, 3226474132, 31079221500, 303907314960, 3010947401340, 30176604541890, 305544118531410, 3122029001183400, 32162924697555960, 333798776316127980, 3487606641543204180, 36662847052669011720, 387575171486963664750]

cp's OEIS Frontend

A151341 Number of walks within N^2 (the first quadrant of Z^2) starting and ending at (0,0) and consisting of 2 n steps taken from {(-1, -1), (-1, 0), (-1, 1), (1, 0)}.

Table of values

List of values