A236973 Number of (n+1)X(1+1) 0..3 arrays with the maximum plus the upper median minus the minimum of every 2X2 subblock equal

256, 1238, 6024, 31008, 160764, 849024, 4508480, 24165576, 130044760, 703680344, 3818629248, 20793569096, 113460899768, 620474785528, 3398136247248, 18637788171496, 102330560045880, 562407959930776, 3093358168328656

Offset

1,1

Comments

Column 1 of A236979

Links

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

Formula

Empirical: a(n) = 13*a(n-1) +42*a(n-2) -1146*a(n-3) +730*a(n-4) +45238*a(n-5) -91716*a(n-6) -1057776*a(n-7) +3000135*a(n-8) +16310461*a(n-9) -56534174*a(n-10) -174338794*a(n-11) +713473424*a(n-12) +1315995560*a(n-13) -6415058232*a(n-14) -6942637052*a(n-15) +42386327376*a(n-16) +23999583512*a(n-17) -208999865648*a(n-18) -40204212816*a(n-19) +773126646240*a(n-20) -72301086496*a(n-21) -2138887142464*a(n-22) +691733245056*a(n-23) +4373056769152*a(n-24) -2270585247232*a(n-25) -6454028894208*a(n-26) +4519617474560*a(n-27) +6589427142656*a(n-28) -5880822898688*a(n-29) -4285047160832*a(n-30) +4950176727040*a(n-31) +1439725223936*a(n-32) -2525199532032*a(n-33) -30528110592*a(n-34) +670609440768*a(n-35) -107673026560*a(n-36) -62080942080*a(n-37) +13411287040*a(n-38) +629145600*a(n-39)

Example

Some solutions for n=5
..1..2....1..2....1..2....0..3....2..0....0..3....1..1....1..0....2..3....2..3
..2..2....1..0....2..3....0..1....3..1....3..0....2..2....2..0....1..3....0..3
..1..2....2..0....3..2....1..3....3..1....2..3....2..1....1..0....3..2....3..3
..2..1....1..0....1..2....0..1....1..3....3..0....2..2....2..1....3..1....0..3
..2..2....0..2....2..0....2..2....0..2....1..3....1..2....1..0....0..2....2..3
..3..2....1..0....2..0....0..1....1..3....3..0....2..1....1..2....1..3....3..0

Crossrefs

Sequence in context: A237007 A237000 A236979 * A237956 A237241 A120054

Adjacent sequences: A236970 A236971 A236972 * A236974 A236975 A236976

Keyword

nonn

Author

R. H. Hardin, Feb 02 2014

Status

approved