|
%I #5 Dec 18 2015 18:18:13
%S 0,16,3456,12931216,655816458528,473216230511351044,
%T 4822507485300347026181088,695298786420085228281048744405924,
%U 1417923660297801516897331705897083237291008
%N Number of city-block distance 1, pressure limit 2 movements in an n X n array with each element moving exactly one horizontally or vertically and no element acquiring more than two neighbors
%C Diagonal of A217028
%e Some solutions for n=3 (movement: 0=n 1=e 2=s 3=w)
%e ..2..1..3....2..3..3....1..2..3....2..3..2....1..3..2....1..1..2....1..2..3
%e ..2..3..0....1..1..3....2..1..0....2..1..0....2..3..2....2..2..3....2..3..0
%e ..1..0..3....1..3..3....1..1..3....0..1..3....0..1..3....0..0..3....0..0..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Sep 24 2012
| 