A221829 - cp's OEIS frontend

A221829 Number of 2 X n arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops or left turns.

n	a(n)
1	0
2	3
3	16
4	73
5	333
6	1519
7	6929
8	31607
9	144177
10	657671
11	3000001
12	13684663
13	62423313
14	284747239
15	1298889569
16	5924953367
17	27026987697
18	123285031751
19	562371183361
20	2565285853303
21	11701686899793
22	53377862792359
23	243485940162209

[0, 3, 16, 73, 333, 1519, 6929, 31607, 144177, 657671, 3000001, 13684663, 62423313, 284747239, 1298889569, 5924953367, 27026987697, 123285031751, 562371183361, 2565285853303, 11701686899793, 53377862792359, 243485940162209]

cp's OEIS Frontend

A221829 Number of 2 X n arrays of occupancy after each element moves to some horizontal, vertical or antidiagonal neighbor, without 2-loops or left turns.

Table of values

List of values