A282964 - OEIS

%I #4 Feb 25 2017 17:45:11

%S 0,5,38,309,2012,12160,70722,395223,2150350,11454117,59948615,

%T 309270883,1576188831,7949681739,39734943909,197045928939,

%U 970369807931,4749163345697,23114719065210,111941467863241,539671083601641

%N Number of nX3 0..1 arrays with no 1 equal to more than one of its horizontal, vertical and antidiagonal neighbors, with the exception of exactly two elements.

%C Column 3 of A282969.

%H R. H. Hardin, <a href="/A282964/b282964.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +24*a(n-2) +7*a(n-3) -267*a(n-4) -870*a(n-5) -639*a(n-6) +3738*a(n-7) +16311*a(n-8) +37667*a(n-9) +61221*a(n-10) +74643*a(n-11) +67169*a(n-12) +38199*a(n-13) -30*a(n-14) -29442*a(n-15) -38079*a(n-16) -27174*a(n-17) -8230*a(n-18) +6285*a(n-19) +10539*a(n-20) +6972*a(n-21) +1605*a(n-22) -1506*a(n-23) -1799*a(n-24) -753*a(n-25) +57*a(n-26) +265*a(n-27) +111*a(n-28) +3*a(n-29) -24*a(n-30) -6*a(n-31) +a(n-33)

%e Some solutions for n=4

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

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

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

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

%Y Cf. A282969.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 25 2017