A230465 Number of nX4 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero

0, 36, 2398, 76518, 2593962, 89087722, 3045192312, 104165339046, 3563285452080, 121887992143256, 4169415853194504, 142622935167746860, 4878692038168963406, 166885068627256229900, 5708625519794794189586, 195274541622754513824870

Offset

1,2

Comments

Column 4 of A230469

Links

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

Formula

Empirical: a(n) = 32*a(n-1) +80*a(n-2) +240*a(n-3) -12842*a(n-4) -17792*a(n-5) -132265*a(n-6) -366801*a(n-7) +47024*a(n-8) +1005370*a(n-9) -553477*a(n-10) +4561400*a(n-11) -1643703*a(n-12) -898500*a(n-13) +4633908*a(n-14) -443679*a(n-15) -4633194*a(n-16) +715486*a(n-17) +824766*a(n-18) -483564*a(n-19) -38952*a(n-20) +33840*a(n-21)

Example

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

Crossrefs

Sequence in context: A135626 A064566 A375058 * A120466 A202633 A198639

Adjacent sequences: A230462 A230463 A230464 * A230466 A230467 A230468

Keyword

nonn

Author

R. H. Hardin, Oct 20 2013

Status

approved