A284778 - cp's OEIS frontend

A284778 Number of self-avoiding planar walks of length n+1 starting at (0,0), ending at (n,0), remaining in the first quadrant and using steps (0,1), (1,0), (1,1), (-1,1), and (1,-1) with the restriction that (0,1) is never used below the diagonal and (1,0) is never used above the diagonal.

n	a(n)
0	0
1	1
2	1
3	4
4	8
5	22
6	54
7	142
8	370
9	983
10	2627
11	7086
12	19238
13	52561
14	144377
15	398518
16	1104794
17	3074809
18	8588093
19	24064642
20	67630898
21	190584766
22	538412426
23	1524554956
24	4326119748
25	12300296227
26	35037658099
27	99977847308
28	285741659312
29	817901027070
30	2344475178110

[0, 1, 1, 4, 8, 22, 54, 142, 370, 983, 2627, 7086, 19238, 52561, 144377, 398518, 1104794, 3074809, 8588093, 24064642, 67630898, 190584766, 538412426, 1524554956, 4326119748, 12300296227, 35037658099, 99977847308, 285741659312, 817901027070, 2344475178110]

cp's OEIS Frontend

A284778 Number of self-avoiding planar walks of length n+1 starting at (0,0), ending at (n,0), remaining in the first quadrant and using steps (0,1), (1,0), (1,1), (-1,1), and (1,-1) with the restriction that (0,1) is never used below the diagonal and (1,0) is never used above the diagonal.

Table of values

List of values