A301356 - OEIS

%I #4 Mar 19 2018 09:50:42

%S 1,6,13,34,92,256,721,2036,5701,15848,43916,121825,338722,943311,

%T 2628900,7326706,20413096,56853677,158313447,440815860,1227496584,

%U 3418358547,9520049340,26513664655,73841105634,205645969535,572712412815

%N Number of nX3 0..1 arrays with every element equal to 1, 2, 4, 5 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 3 of A301361.

%H R. H. Hardin, <a href="/A301356/b301356.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 8*a(n-1) -26*a(n-2) +47*a(n-3) -60*a(n-4) +74*a(n-5) -85*a(n-6) +71*a(n-7) -68*a(n-8) +56*a(n-9) -10*a(n-10) +72*a(n-11) -8*a(n-12) -148*a(n-13) -108*a(n-14) -6*a(n-15) +182*a(n-16) +168*a(n-17) +76*a(n-18) -38*a(n-19) -60*a(n-20) -64*a(n-21) -62*a(n-22) +49*a(n-24) +28*a(n-25) -10*a(n-26) -17*a(n-27) -2*a(n-28) +6*a(n-29) +a(n-30) -a(n-31)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A301361.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 19 2018