A231077 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 at least one element with value (x(i,j)-1) mod 3, and upper left element zero

0, 40, 136, 6400, 71944, 1866192, 32292680, 679262904, 13081009496, 262832968576, 5182051255656, 103098503270144, 2042906229701640, 40558460980862344, 804524501026875864, 15965241050999242720, 316760803542953380040

Offset

1,2

Comments

Column 4 of A231080

Links

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

Formula

Empirical: a(n) = 19*a(n-1) +101*a(n-2) -1584*a(n-3) -1954*a(n-4) -301*a(n-5) +64545*a(n-6) +333008*a(n-7) +1088515*a(n-8) -6873022*a(n-9) +6122504*a(n-10) -31836070*a(n-11) +269756531*a(n-12) -1031985683*a(n-13) -1969070017*a(n-14) +13183670776*a(n-15) -7804506767*a(n-16) -34501283784*a(n-17) +28415803783*a(n-18) +71061102200*a(n-19) -40339615785*a(n-20) -126321136798*a(n-21) +20350941417*a(n-22) +164969153543*a(n-23) +22060201296*a(n-24) -152405464476*a(n-25) -46608742972*a(n-26) +113641646544*a(n-27) +23731810624*a(n-28) -58758074368*a(n-29) -811932672*a(n-30) +17051844608*a(n-31) -2394341376*a(n-32) -2392915968*a(n-33) +480509952*a(n-34) +232783872*a(n-35) -62914560*a(n-36)

Example

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

Crossrefs

Sequence in context: A260536 A251137 A251130 * A044372 A044753 A160148

Adjacent sequences: A231074 A231075 A231076 * A231078 A231079 A231080

Keyword

nonn

Author

R. H. Hardin, Nov 03 2013

Status

approved