|
%I #4 Aug 12 2018 19:43:12
%S 4,14,45,133,419,1382,4495,14754,48525,159584,524981,1727658,5685321,
%T 18710300,61576790,202655046,666960573,2195053580,7224214965,
%U 23775889227,78249787781,257531127865,847571571085,2789478970713,9180573908293
%N Number of nX3 0..1 arrays with every element unequal to 0, 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
%C Column 3 of A318024.
%H R. H. Hardin, <a href="/A318019/b318019.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) +4*a(n-2) -5*a(n-3) -14*a(n-4) -17*a(n-5) +18*a(n-6) +29*a(n-7) +23*a(n-8) +12*a(n-9) -27*a(n-10) -27*a(n-11) -16*a(n-12) -7*a(n-13) -5*a(n-14) +18*a(n-15) -9*a(n-16) +9*a(n-17) -3*a(n-18) for n>23
%e Some solutions for n=5
%e ..0..1..1. .0..0..0. .0..1..1. .0..1..1. .0..0..1. .0..1..0. .0..1..1
%e ..1..1..0. .0..1..0. .1..1..0. .1..1..1. .0..1..1. .0..0..0. .0..1..0
%e ..1..0..0. .1..1..0. .1..1..1. .0..1..1. .1..1..0. .0..0..0. .0..0..0
%e ..0..0..1. .1..1..0. .1..1..1. .1..1..1. .1..1..1. .0..0..1. .0..0..0
%e ..0..1..1. .1..1..0. .1..1..1. .1..0..1. .1..0..1. .0..0..0. .0..0..0
%Y Cf. A318024.
%K nonn
%O 1,1
%A _R. H. Hardin_, Aug 12 2018
| 