A252859 - OEIS

%I #4 Dec 23 2014 15:47:29

%S 11286,4986,6795,13590,28728,60588,126306,266391,562293,1185867,

%T 2491002,5266044,11098008,23380335,49262301,103991625,219100158,

%U 461718972,973617264,2053180017,4326686289,9121144149,19232567028,40543286472

%N Number of (n+2)X(6+2) 0..2 arrays with every consecutive three elements in every row, column, diagonal and antidiagonal having exactly two distinct values, and new values 0 upwards introduced in row major order

%C Column 6 of A252861

%H R. H. Hardin, <a href="/A252859/b252859.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = -a(n-1) +4*a(n-3) +16*a(n-4) +16*a(n-5) +9*a(n-6) -11*a(n-7) -58*a(n-8) -64*a(n-9) -14*a(n-10) +79*a(n-11) +143*a(n-12) +104*a(n-13) +13*a(n-14) -101*a(n-15) -124*a(n-16) -74*a(n-17) +2*a(n-18) +34*a(n-19) +28*a(n-20) +8*a(n-21) -4*a(n-22) -4*a(n-23) for n>26

%e Some solutions for n=4

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

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Dec 23 2014