A253691 - OEIS

%I #5 Jan 09 2015 08:43:51

%S 16,76,234,700,1632,3042,6558,14710,30864,74332,143078,301840,595924,

%T 1315998,2668860,6102208,11569664,25167926,48101064,108872328,

%U 212350500,492777890,912037666,2072968028,3852486610,9062325392,17036265558

%N Number of (n+1)X(n+1) 0..1 arrays with every 2X2 subblock ne-sw antidiagonal difference unequal to its neighbors horizontally and nw+se diagonal sum unequal to its neighbors vertically

%C Diagonal of A253698

%H R. H. Hardin, <a href="/A253691/b253691.txt">Table of n, a(n) for n = 1..29</a>

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 09 2015