cp's OEIS Frontend

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).

%I A207996 #12 Nov 23 2015 09:00:12
%S A207996 32,729,17749,441090,11045757,277458045,6978332618,175605187731,
%T A207996 4419979346851,111261280858024,2800819361992659,70507189155056781,
%U A207996 1774944424628356230,44682493917576202087,1124839588414204665607
%N 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).
%C A207996 Column 7 of A207997.
%H A207996 R. H. Hardin, <a href="/A207996/b207996.txt">Table of n, a(n) for n = 1..210</a>
%F A207996 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).
%F A207996 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
%e A207996 Some solutions for n=4
%e A207996 ..0..1..0..2..1..2..0....0..1..2..1..2..0..1....0..1..2..1..2..0..1
%e A207996 ..2..0..1..0..2..1..2....2..0..1..2..0..2..0....1..2..1..2..0..1..2
%e A207996 ..0..1..0..1..0..2..0....0..1..2..1..2..1..2....2..0..2..1..2..0..1
%e A207996 ..2..0..2..0..1..0..1....1..0..1..2..1..2..0....0..1..0..2..0..1..2
%K A207996 nonn
%O A207996 1,1
%A A207996 _R. H. Hardin_, Feb 22 2012