A221731 - cp's OEIS frontend

A221731 Number of n X 2 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out left turns.

n	a(n)
1	3
2	17
3	91
4	489
5	2627
6	14113
7	75819
8	407321
9	2188243
10	11755857
11	63155771
12	339290569
13	1822764387
14	9792403073
15	52607544139
16	282622526841
17	1518327722483
18	8156883666097
19	43821073775451
20	235419136209449
21	1264737828598147

[3, 17, 91, 489, 2627, 14113, 75819, 407321, 2188243, 11755857, 63155771, 339290569, 1822764387, 9792403073, 52607544139, 282622526841, 1518327722483, 8156883666097, 43821073775451, 235419136209449, 1264737828598147]

cp's OEIS Frontend

A221731 Number of n X 2 arrays of occupancy after each element stays put or moves to some horizontal or antidiagonal neighbor, without move-in move-out left turns.

Table of values

List of values