A230922 Number of nX4 0..2 arrays x(i,j) with each element horizontally, vertically, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero

0, 432, 8748, 559872, 28978992, 1509045552, 79222650048, 4146049651392, 217126339216128, 11369937986534592, 595387976257771200, 31177761046838020800, 1632634490394925956288, 85493509927692733685952

Offset

1,2

Comments

Column 4 of A230926

Links

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

Formula

Empirical: a(n) = 39*a(n-1) +624*a(n-2) +4268*a(n-3) -17754*a(n-4) +128856*a(n-5) -345592*a(n-6) +557424*a(n-7) -939312*a(n-8) -946592*a(n-9) -489504*a(n-10) -318144*a(n-11) -475904*a(n-12) -49152*a(n-13) +15360*a(n-14) +4096*a(n-15)

Example

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

Crossrefs

Sequence in context: A236279 A223595 A223436 * A109123 A223688 A269183

Adjacent sequences: A230919 A230920 A230921 * A230923 A230924 A230925

Keyword

nonn

Author

R. H. Hardin, Nov 01 2013

Status

approved