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A318010 Number of nX2 0..1 arrays with every element unequal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero. 2

%I #4 Aug 12 2018 19:33:17

%S 2,8,28,97,338,1178,4105,14305,49850,173717,605368,2109583,7351463,

%T 25618337,89274637,311103754,1084132616,3777979256,13165480909,

%U 45878993986,159878860766,557144956745,1941535618525,6765852427390

%N Number of nX2 0..1 arrays with every element unequal to 0, 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Column 2 of A318016.

%H R. H. Hardin, <a href="/A318010/b318010.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 4*a(n-1) -2*a(n-2) +a(n-3) -a(n-4)

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A318016.

%K nonn

%O 1,1

%A _R. H. Hardin_, Aug 12 2018

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Last modified March 2 10:43 EST 2024. Contains 370466 sequences. (Running on oeis4.)