A300430 - OEIS

%I #4 Mar 05 2018 14:48:16

%S 1,6,13,33,87,228,611,1656,4479,12100,32579,87705,236468,638292,

%T 1723867,4656414,12576659,33964397,91716558,247664253,668787690,

%U 1806042197,4877289821,13171458556,35570422970,96059902903,259414009161

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

%C Column 3 of A300435.

%H R. H. Hardin, <a href="/A300430/b300430.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 7*a(n-1) -19*a(n-2) +26*a(n-3) -20*a(n-4) +16*a(n-5) -21*a(n-6) +14*a(n-7) -6*a(n-8) +7*a(n-9) -25*a(n-10) +42*a(n-11) +42*a(n-12) -29*a(n-13) -71*a(n-14) -56*a(n-15) -15*a(n-16) +28*a(n-17) +78*a(n-18) +86*a(n-19) +54*a(n-20) -7*a(n-21) -26*a(n-22) -14*a(n-23) -5*a(n-24) -13*a(n-25) -11*a(n-26) +6*a(n-28) +4*a(n-29) -a(n-31)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A300435.

%K nonn

%O 1,2

%A _R. H. Hardin_, Mar 05 2018