A230736 Number of (n+3)X(2+3) 0..2 black square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero

8, 66, 244, 2016, 6576, 54138, 173428, 1427040, 4558536, 37506738, 119758148, 985334832, 3145930352, 25883741898, 82639468964, 679931791152, 2170826159272, 17860880147874, 57024624645332, 469180811419968, 1497958570841456

Offset

1,1

Comments

Column 2 of A230739

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 31*a(n-2) -126*a(n-4) +42*a(n-6) +79*a(n-8) -a(n-10) +8*a(n-12)

Example

Some solutions for n=3
..x..0..x..0..x....x..0..x..1..x....x..0..x..2..x....x..0..x..0..x
..2..x..1..x..1....1..x..2..x..0....2..x..1..x..0....2..x..1..x..2
..x..1..x..2..x....x..2..x..1..x....x..1..x..1..x....x..2..x..2..x
..0..x..0..x..1....1..x..0..x..0....0..x..2..x..0....0..x..0..x..1
..x..0..x..2..x....x..2..x..2..x....x..0..x..2..x....x..1..x..0..x
..2..x..1..x..1....1..x..1..x..1....2..x..1..x..1....0..x..2..x..2

Crossrefs

Sequence in context: A015496 A226126 A039329 * A008893 A168302 A121782

Adjacent sequences: A230733 A230734 A230735 * A230737 A230738 A230739

Keyword

nonn

Author

R. H. Hardin, Oct 28 2013

Status

approved