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).

32, 729, 17749, 441090, 11045757, 277458045, 6978332618, 175605187731, 4419979346851, 111261280858024, 2800819361992659, 70507189155056781, 1774944424628356230, 44682493917576202087, 1124839588414204665607

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