A230943 Number of (n+3) X (2+3) 0..3 white square subarrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, and upper left element zero.

16, 34, 724, 1994, 28128, 76682, 1144652, 3107746, 46058744, 125263570, 1857863476, 5050618938, 74908095984, 203655079130, 3020446141788, 8211674722322, 121789649054696, 331109620080930, 4910772371719684

Offset

1,1

Comments

Column 2 of A230949.

Links

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

Formula

Empirical: a(n) = 31*a(n-2) +375*a(n-4) +233*a(n-6) -7946*a(n-8) -884*a(n-10) -16296*a(n-12) -203520*a(n-14) +53120*a(n-16).

Example

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

Crossrefs

Cf. A230949.

Sequence in context: A185459 A279712 A228800 * A070589 A104910 A161441

Adjacent sequences: A230940 A230941 A230942 * A230944 A230945 A230946

Keyword

nonn

Author

R. H. Hardin, Nov 01 2013

Status

approved