A205155 - OEIS

%I #7 Feb 22 2020 20:54:24

%S 1,15,6941,54314298,4826926610498,4948963310952700521

%N Number of n X n 0..3 arrays with no occurrence of three equal elements in a row horizontally, vertically or nw-to-se diagonally, and new values 0..3 introduced in row major order

%C Diagonal of A205161

%e Some solutions for n=5

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

%e ..2..1..3..2..2....0..2..2..1..0....1..1..2..3..3....1..1..2..2..3

%e ..2..2..3..2..2....3..1..0..1..0....3..2..0..0..2....3..0..3..3..0

%e ..3..1..1..3..1....0..0..1..2..1....1..1..3..1..0....0..3..3..0..2

%e ..1..2..1..3..2....3..3..0..2..0....0..1..0..2..3....1..0..1..0..1

%K nonn

%O 1,2

%A _R. H. Hardin_ Jan 22 2012