A230677 Number of 3Xn 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value 2-x(i,j)

0, 81, 1173, 18915, 340563, 6081561, 108108231, 1923264723, 34219066161, 608809697883, 10831633601715, 192711252863829, 3428626492612815, 61000479835023903, 1085291316379044081, 19308983258977687575

Offset

1,2

Comments

Row 3 of A230675

Links

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

Formula

Empirical: a(n) = 13*a(n-1) +65*a(n-2) +312*a(n-3) +829*a(n-4) +559*a(n-5) -458*a(n-6) -2767*a(n-7) -2801*a(n-8) -1031*a(n-9) -485*a(n-10) -743*a(n-11) -272*a(n-12) +332*a(n-13) +172*a(n-14) -24*a(n-15) for n>16

Example

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

Crossrefs

Sequence in context: A237059 A374144 A236010 * A231994 A236790 A232876

Adjacent sequences: A230674 A230675 A230676 * A230678 A230679 A230680

Keyword

nonn

Author

R. H. Hardin, Oct 27 2013

Status

approved