A275507 - OEIS

%I #8 Feb 04 2019 13:57:57

%S 48,200,1168,7140,43780,268152,1643372,10069540,61703488,378096660,

%T 2316847540,14196847960,86993404476,533065762516,3266444015616,

%U 20015648328132,122649024958372,751551142797496,4605247533843404

%N Number of 7 X n 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.

%H R. H. Hardin, <a href="/A275507/b275507.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) + 18*a(n-2) + 11*a(n-3) - 23*a(n-4) - 4*a(n-5) for n>6.

%F Empirical g.f.: 4*x*(12 + 14*x - 74*x^2 - 123*x^3 + 60*x^4 + 59*x^5) / (1 - 3*x - 18*x^2 - 11*x^3 + 23*x^4 + 4*x^5). - _Colin Barker_, Feb 04 2019

%e Some solutions for n=4:

%e ..0..1..1..1. .0..1..1..2. .0..1..1..1. .0..0..1..1. .0..0..1..2

%e ..1..2..2..2. .1..1..2..0. .0..1..2..2. .1..1..2..2. .1..1..2..2

%e ..2..2..0..0. .2..2..2..0. .1..2..2..0. .2..2..2..0. .1..2..2..0

%e ..2..0..1..1. .2..0..0..1. .2..2..0..0. .2..0..0..0. .2..0..0..0

%e ..0..1..1..2. .0..0..1..1. .2..0..0..1. .0..1..1..1. .0..0..1..1

%e ..1..1..2..2. .0..1..1..2. .0..0..1..1. .0..1..2..2. .0..1..1..2

%e ..1..2..0..0. .1..2..2..2. .0..1..2..2. .2..2..0..0. .1..2..2..0

%Y Row 7 of A275504.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jul 30 2016