cp's OEIS Frontend

A221506 Number of nX4 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.

%I A221506 #5 Jul 23 2025 02:00:39
%S A221506 1,446,31663,2691211,219689604,18054912942,1481559445366,
%T A221506 121595969760961,9979148121938539,818972532183106546,
%U A221506 67211557641378928789,5515926988608836197348
%N A221506 Number of nX4 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.
%C A221506 Column 4 of A221507
%e A221506 Some solutions for n=3
%e A221506 ..1..0..1..0....0..2..2..1....0..0..1..1....1..2..0..1....0..1..0..1
%e A221506 ..0..3..1..3....2..2..0..1....2..4..1..1....1..0..3..1....2..1..3..2
%e A221506 ..2..0..1..0....1..0..1..0....1..0..1..0....1..2..0..0....1..1..0..0
%K A221506 nonn
%O A221506 1,2
%A A221506 _R. H. Hardin_ Jan 18 2013