A199641 - cp's OEIS frontend

A199641 Number of n X 2 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

n	a(n)
1	1
2	3
3	13
4	60
5	288
6	1384
7	6628
8	31772
9	152304
10	730036
11	3499340
12	16773680
13	80402532
14	385399644
15	1847365808
16	8855120468
17	42445929772
18	203459338800
19	975257291396
20	4674775757500
21	22407962058928
22	107409807372276
23	514855687878924

[1, 3, 13, 60, 288, 1384, 6628, 31772, 152304, 730036, 3499340, 16773680, 80402532, 385399644, 1847365808, 8855120468, 42445929772, 203459338800, 975257291396, 4674775757500, 22407962058928, 107409807372276, 514855687878924]

cp's OEIS Frontend

A199641 Number of n X 2 0..2 arrays with values 0..2 introduced in row major order and each element equal to one or two horizontal and vertical neighbors.

Table of values

List of values