A281470 - OEIS

%I #6 May 14 2017 12:55:02

%S 2,8,17,37,78,169,361,778,1673,3605,7774,16777,36241,78338,169465,

%T 366829,794550,1721977,3733929,8100666,17582281,38178181,82932878,

%U 180217513,391754433,851856306,1852865241,4031221917,8772754342,19095598617

%N Number of 2Xn 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

%C Row 2 of A281469.

%H R. H. Hardin, <a href="/A281470/b281470.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +a(n-2) -6*a(n-3) -2*a(n-4) +4*a(n-5) for n>6

%F Empirical g.f.: 2*x -x^2*(8-7*x-22*x^2-2*x^3+16*x^4) /(2*x-1) /(2*x^4-3*x^2-x+1) . - _R. J. Mathar_, May 14 2017

%e Some solutions for n=4

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

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

%Y Cf. A281469.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 22 2017