A231077 Number of n X 4 0..3 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, 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

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

Column 4 of A231080.

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