login
Number of n X n 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
1

%I #7 Apr 14 2020 21:32:10

%S 1,6,20,67,393,4133,86487,3590263,285034170,43174729552,

%T 12383193287684,6712873423988949,6871475875643572553,

%U 13272675681120501977922,48367944991570243925176462,332490278773637201581189154380

%N Number of n X n 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Diagonal of A318343.

%H R. H. Hardin, <a href="/A318337/b318337.txt">Table of n, a(n) for n = 1..17</a>

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A318343.

%K nonn

%O 1,2

%A _R. H. Hardin_, Aug 24 2018