A221440 - cp's OEIS frontend

A221440 Hilltop maps: number of n X 2 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..1 n X 2 array.

n	a(n)
1	3
2	9
3	31
4	105
5	355
6	1201
7	4063
8	13745
9	46499
10	157305
11	532159
12	1800281
13	6090307
14	20603361
15	69700671
16	235795681
17	797691075
18	2698569577
19	9129195487
20	30883847113
21	104479306403
22	353450961809
23	1195716038943
24	4045078385041
25	13684402155875

[3, 9, 31, 105, 355, 1201, 4063, 13745, 46499, 157305, 532159, 1800281, 6090307, 20603361, 69700671, 235795681, 797691075, 2698569577, 9129195487, 30883847113, 104479306403, 353450961809, 1195716038943, 4045078385041, 13684402155875]

cp's OEIS Frontend

A221440 Hilltop maps: number of n X 2 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..1 n X 2 array.

Table of values

List of values