A198406 Number of 2nX4 0..4 arrays with values 0..4 introduced in row major order and each element equal to exactly one horizontal and vertical neighbor.

17, 6986, 5057327, 3850206168, 2970439193698, 2302126761338667, 1786986687280410199, 1387873766175721022708, 1078103379003130131290922, 837527575449508082133268374, 650650234699083836241245595580

Offset

1,1

Comments

Column 2 of A198408

Links

R. H. Hardin, Table of n, a(n) for n = 1..135

Formula

Empirical: a(n) = 1403*a(n-1) -637645*a(n-2) +137282333*a(n-3) -17017714367*a(n-4) +1364835298243*a(n-5) -76639410634114*a(n-6) +3191366177314634*a(n-7) -102913245326634650*a(n-8) +2655110974709252514*a(n-9) -56105822107307497543*a(n-10) +986291475398066357197*a(n-11) -14549934304060747863295*a(n-12) +180604873121644318910345*a(n-13) -1880215342434918795708997*a(n-14) +16254501107654334238806623*a(n-15) -114428672751561876621350678*a(n-16) +631796189983881823704565522*a(n-17) -2514321032336880134392479756*a(n-18) +5347925101122342370566753634*a(n-19) +9727097826445051324997106402*a(n-20) -128973865442223470466372714984*a(n-21) +465544733754837597013298998827*a(n-22) -452575413995937575160149012181*a(n-23) -2669948561041586277470250159363*a(n-24) +11565485561630547478023894101581*a(n-25) -16146119733854251357028067166756*a(n-26) -8753254832493873362667789236224*a(n-27) +58162767920126386894334761207152*a(n-28) -65759776655639630497334323555328*a(n-29) -36048573355990958566455357654016*a(n-30) +220374955211415260610303706521600*a(n-31) -246003161005043287245236845346816*a(n-32) +33143330588113400413743791472640*a(n-33) +111832429636351618804204019122176*a(n-34) -527529315734277197932414805999616*a(n-35) +519859245372628057219452981215232*a(n-36) +1058694475776505431333536985513984*a(n-37) -841679624865003962817729917878272*a(n-38) -469208913796894475374119736049664*a(n-39) -2462121704883366053036660902330368*a(n-40) -1323072206112891113034422943744000*a(n-41) +641861325273108040372018477006848*a(n-42) +3343601496131615061986933414559744*a(n-43)

Example

Some solutions for n=3
..0..1..0..0....0..1..0..0....0..1..0..0....0..1..0..0....0..1..0..0
..0..1..2..2....0..1..2..2....0..1..2..2....0..1..2..2....0..1..2..2
..1..2..1..1....3..3..1..1....3..3..0..0....3..3..1..0....1..3..1..1
..1..2..3..3....0..0..4..0....2..4..1..1....4..4..1..0....1..3..0..2
..2..3..1..0....1..2..4..0....2..4..0..0....1..2..3..2....4..2..0..2
..2..3..1..0....1..2..1..1....1..1..2..2....1..2..3..2....4..2..4..4

Crossrefs

Sequence in context: A344148 A243481 A287038 * A198533 A192766 A166326

Adjacent sequences: A198403 A198404 A198405 * A198407 A198408 A198409

Keyword

nonn

Author

R. H. Hardin, Oct 24 2011

Status

approved