A186931 - OEIS

A186931

Number of (n+1) X (n+1) binary arrays with every 2 X 2 subblock trace equal to exactly one or two horizontal and vertical neighbor 2 X 2 subblock traces.

%I #8 May 10 2021 01:08:22

%S 0,104,1840,59720,3026432,264604776,35582947920,8132915749352,

%T 2989994168957168

%N Number of (n+1) X (n+1) binary arrays with every 2 X 2 subblock trace equal to exactly one or two horizontal and vertical neighbor 2 X 2 subblock traces.

%C Diagonal of A186939.

%e Some solutions for 4 X 4

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

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

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

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

%Y Cf. A186939.

%K nonn

%O 1,2

%A _R. H. Hardin_ Mar 01 2011