A280438 - OEIS

%I #7 Feb 13 2019 11:00:56

%S 10,68,136,232,360,548,834,1284,2008,3188,5128,8332,13638,22436,37032,

%T 61248,101416,168020,278410,461284,764088,1265228,2094216,3464892,

%U 5730190,9472388,15651784,25851544,42680808,70438148,116203218,191632452

%N Number of n X 6 0..1 arrays with no element equal to more than one of its horizontal and vertical neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.

%H R. H. Hardin, <a href="/A280438/b280438.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) - 4*a(n-2) - 2*a(n-3) + 4*a(n-4) - a(n-6) for n>7.

%F Empirical g.f.: 2*x*(5 + 14*x - 48*x^2 - 10*x^3 + 36*x^4 + 18*x^5 + 6*x^6) / ((1 - x)^2*(1 - x - x^2)^2). - _Colin Barker_, Feb 13 2019

%e Some solutions for n=4:

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

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

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

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

%Y Column 6 of A280440.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 03 2017