A300026 - OEIS

%I #6 Jun 15 2020 15:04:04

%S 1,4,3,80,1637,18775,1841903,326461365,50773963070,27507422939178

%N Number of n X n 0..1 arrays with every element equal to 0, 1, 3, 4, 6, 7 or 8 king-move adjacent elements, with upper left element zero.

%C Diagonal of A300030.

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A300030.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 23 2018