login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Number of n X n 0..1 arrays with no element equal to more than two of its horizontal, diagonal or 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 13:02:30

%S 0,0,131,1020,5892,23216,84474,285076,886900,2652496,7689224,21516104,

%T 58884471

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

%C Diagonal of A281400.

%e Some solutions for n=4

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

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

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

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

%Y Cf. A281400.

%K nonn

%O 1,3

%A _R. H. Hardin_, Jan 21 2017