A301959 - OEIS

%I #4 Mar 29 2018 12:58:40

%S 3,6,16,40,100,252,632,1588,3988,10016,25156,63180,158680,398532,

%T 1000932,2513888,6313748,15857276,39826296,100025620,251219060,

%U 630948512,1584656932,3979940588,9995808408,25104944036,63052250436,158358699360

%N Number of nX3 0..1 arrays with every element equal to 0, 1 or 4 horizontally or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A301964.

%H R. H. Hardin, <a href="/A301959/b301959.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = a(n-1) +3*a(n-2) +2*a(n-3)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A301964.

%K nonn

%O 1,1

%A _R. H. Hardin_, Mar 29 2018