%I #5 Mar 31 2012 12:37:28
%S 1,2,16,122,690,4098,24301,131984,720033,3945050,21470933,115976303,
%T 629975658,3432416744,18721854079,102389248936,560740694837,
%U 3070272326544,16802201754590,91916873329401,502611764211182
%N Number of nX2 1..3 arrays with every element value z a city block distance of exactly z from another element value z
%C Column 2 of A209365
%H R. H. Hardin, <a href="/A209361/b209361.txt">Table of n, a(n) for n = 1..210</a>
%e Some solutions for n=5
%e ..2..3....1..3....2..3....3..3....1..2....1..3....2..2....2..3....3..2....3..3
%e ..2..2....1..2....3..2....2..2....1..1....1..3....1..1....2..2....3..3....3..3
%e ..3..2....2..2....3..2....3..2....3..2....3..3....2..2....3..2....2..2....3..3
%e ..1..1....2..3....2..2....3..2....1..1....1..1....1..1....2..1....3..3....1..3
%e ..1..2....2..2....3..2....2..2....1..3....3..3....1..2....1..1....2..2....1..3
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 06 2012