A280956 - OEIS

%I #4 Jan 11 2017 15:13:44

%S 4,42,241,1554,9899,63085,402077,2562733,16334111,104108376,663554669,

%T 4229292041,26956196587,171810442122,1095066516245,6979614612419,

%U 44485900541127,283539343806484,1807191908208865,11518481171610485

%N Number of nX3 0..2 arrays with no element equal to more than one of its horizontal, vertical and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.

%C Column 3 of A280961.

%H R. H. Hardin, <a href="/A280956/b280956.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 5*a(n-1) +8*a(n-2) +5*a(n-3) +4*a(n-4) -35*a(n-5) +2*a(n-6) +71*a(n-7) -11*a(n-8) -38*a(n-9) +6*a(n-10) -8*a(n-11) -8*a(n-12) for n>16

%e Some solutions for n=4

%e ..0..1..0. .0..0..1. .0..1..2. .0..1..2. .0..1..0. .0..0..1. .0..1..1

%e ..1..2..2. .2..2..0. .1..2..0. .2..0..0. .0..2..0. .2..1..2. .0..2..0

%e ..0..1..0. .0..1..2. .0..1..2. .2..1..2. .2..1..2. .2..0..1. .1..0..1

%e ..1..0..1. .1..0..2. .2..1..0. .0..0..1. .1..0..0. .0..2..2. .2..2..0

%Y Cf. A280961.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 11 2017