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Number of n X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
0

%I #6 Apr 21 2020 13:01:37

%S 0,2,56,270,1141,4248,14375,45614,138676,409976,1190740,3421202,

%T 9767347,27782656,78849645

%N Number of n X n 0..1 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%C Diagonal of A281205.

%e Some solutions for n=4

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

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

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

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

%Y Cf. A281205.

%K nonn

%O 1,2

%A _R. H. Hardin_, Jan 17 2017