A302724 - OEIS

%I #4 Apr 12 2018 10:51:46

%S 1,7,22,83,301,1079,4064,15183,55012,207349,770421,2830250,10617371,

%T 39400644,145704104,544623685,2020998479,7497256552,27957348859,

%U 103787074017,385563034716,1435728019366,5332352333196,19821039046245

%N Number of nX3 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A302728.

%H R. H. Hardin, <a href="/A302724/b302724.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +5*a(n-2) +27*a(n-3) -64*a(n-4) -67*a(n-5) +25*a(n-6) -22*a(n-7) -66*a(n-8) -240*a(n-9) +232*a(n-10) +168*a(n-11) -16*a(n-12) +64*a(n-13) +64*a(n-14) +256*a(n-15) -256*a(n-16)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A302728.

%K nonn

%O 1,2

%A _R. H. Hardin_, Apr 12 2018