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A207996 Number of nX7 0..2 arrays with new values 0..2 introduced in row major order and no element equal to any horizontal or vertical neighbor (colorings ignoring permutations of colors). 2
32, 729, 17749, 441090, 11045757, 277458045, 6978332618, 175605187731, 4419979346851, 111261280858024, 2800819361992659, 70507189155056781, 1774944424628356230, 44682493917576202087, 1124839588414204665607 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 7 of A207997.

LINKS

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

FORMULA

a(n) = 55*a(n-1) -1109*a(n-2) +11330*a(n-3) -67206*a(n-4) +247404*a(n-5) -582440*a(n-6) +881876*a(n-7) -846764*a(n-8) +499200*a(n-9) -172400*a(n-10) +33152*a(n-11) -3264*a(n-12) +128*a(n-13).

G.f.: -x*(32 -1031*x +13142*x^2 -89204*x^3 +360470*x^4 -909704*x^5 +1454814*x^6 -1461492*x^7 +896144*x^8 -320568*x^9 +63472*x^10 -6400*x^11 +256*x^12) / ( -1 +55*x -1109*x^2 +11330*x^3 -67206*x^4 +247404*x^5 -582440*x^6 +881876*x^7 -846764*x^8 +499200*x^9 -172400*x^10 +33152*x^11 -3264*x^12 +128*x^13 ). - R. J. Mathar, Nov 23 2015

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A274857 A274754 A008789 * A284227 A297371 A144135

Adjacent sequences:  A207993 A207994 A207995 * A207997 A207998 A207999

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 22 2012

STATUS

approved

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Last modified March 31 16:23 EDT 2020. Contains 333151 sequences. (Running on oeis4.)