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A198281 Number of 2nX8 0..2 arrays with values 0..2 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors 1
4, 52, 662, 8784, 112750, 1478756, 19399132, 254611868, 3341562350, 43867978456, 575917076750, 7560973295748, 99265283146820, 1303224636522612, 17109671915393798, 224628189063611744, 2949082376664452782 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A198285

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..193

FORMULA

Empirical: a(n) = 20*a(n-1) -94*a(n-2) +30*a(n-3) +991*a(n-4) -14152*a(n-5) +57737*a(n-6) +47122*a(n-7) -441218*a(n-8) +2956618*a(n-9) -10811467*a(n-10) -23072476*a(n-11) +84378808*a(n-12) -161949862*a(n-13) +516000620*a(n-14) +2832666716*a(n-15) -3992016864*a(n-16) -5147127328*a(n-17) +8009660032*a(n-18) -125833211136*a(n-19) -133111885824*a(n-20) +321245103104*a(n-21) -748696293376*a(n-22) +5854699044864*a(n-23) +11597031440384*a(n-24) -9315056222208*a(n-25) +725672263680*a(n-26) -167805362634752*a(n-27) -267408019292160*a(n-28) +267698466455552*a(n-29) +891968070615040*a(n-30) +545959062798336*a(n-31) +2070380395102208*a(n-32) +1440360232386560*a(n-33) -14953358137753600*a(n-34) -4644337115725824*a(n-35) +18014398509481984*a(n-36)

EXAMPLE

Some solutions for n=3

..0..0..1..1..0..0..2..2....0..0..0..0..1..1..0..0....0..0..1..1..0..0..1..1

..0..0..1..1..0..0..2..2....0..2..2..0..1..1..0..0....0..0..1..1..0..0..1..1

..2..2..2..2..2..2..0..0....0..2..2..0..2..2..2..2....1..1..0..0..2..2..2..2

..2..0..0..1..1..2..0..0....0..0..0..0..2..1..1..2....1..1..0..0..2..0..0..2

..2..0..0..1..1..2..1..1....2..2..1..1..2..1..1..2....0..0..1..1..2..0..0..2

..2..2..2..2..2..2..1..1....2..2..1..1..2..2..2..2....0..0..1..1..2..2..2..2

CROSSREFS

Sequence in context: A221727 A144339 A155661 * A220933 A222321 A222138

Adjacent sequences:  A198278 A198279 A198280 * A198282 A198283 A198284

KEYWORD

nonn

AUTHOR

R. H. Hardin Oct 23 2011

STATUS

approved

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Last modified May 17 02:47 EDT 2022. Contains 353727 sequences. (Running on oeis4.)