A302815 - OEIS

%I #6 May 26 2024 01:34:17

%S 4,20,75,389,1852,8485,41247,196946,931243,4464289,21314416,101500589,

%T 484945365,2314846870,11042132315,52714123333,251602109008,

%U 1200668947009,5730793024341,27351896253430,130538870872807,623034403841625

%N Number of n X 3 0..1 arrays with every element equal to 0, 1, 2, 4 or 5 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A302820.

%H R. H. Hardin, <a href="/A302815/b302815.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 3*a(n-1) +5*a(n-2) +36*a(n-3) -62*a(n-4) -116*a(n-5) -142*a(n-6) -78*a(n-7) +150*a(n-8) -100*a(n-9) +176*a(n-10) +272*a(n-11) +320*a(n-12) -256*a(n-14).

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A302820.

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 13 2018