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 A241307 Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4 1

%I

%S 5,6,15,25,40,89,121,237,390,682,1250,2069,3698,6352,11013,19408,

%T 33478,58524,101542,176797,307761,535313,932344,1620570,2821554,

%U 4908976,8540842,14866293,25861744,45006289,78311151,136266311,237120535

%N Number of 2Xn 0..3 arrays with no element equal to zero plus the sum of elements to its left or one plus the sum of the elements above it or zero plus the sum of the elements diagonally to its northwest or zero plus the sum of the elements antidiagonally to its northeast, modulo 4

%C Row 2 of A241306

%H R. H. Hardin, <a href="/A241307/b241307.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-2) +3*a(n-3) -a(n-4) -a(n-5) +2*a(n-6) -10*a(n-8) -7*a(n-9) +8*a(n-10) +5*a(n-11) -3*a(n-12) -7*a(n-13) +7*a(n-14) for n>20

%e Some solutions for n=4

%e ..3..2..3..2....3..2..3..3....3..2..3..3....2..3..3..2....3..2..2..2

%e ..3..1..1..2....3..0..1..2....3..1..1..2....2..1..1..2....3..0..0..1

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 18 2014

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Last modified September 22 07:34 EDT 2020. Contains 337289 sequences. (Running on oeis4.)