A240272 - OEIS

%I #4 Apr 03 2014 09:44:12

%S 3,7,35,157,713,3263,14895,68101,311509,1424689,6516312,29807450,

%T 136351053,623728103,2853225545,13052077767,59706884718,273130241113,

%U 1249440509707,5715597380517,26146153523610,119606300969406

%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 one plus the sum of the elements diagonally to its northwest, modulo 4

%C Row 2 of A240271

%H R. H. Hardin, <a href="/A240272/b240272.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 8*a(n-1) -20*a(n-2) +34*a(n-3) -84*a(n-4) +92*a(n-5) -68*a(n-6) +222*a(n-7) +13*a(n-8) -251*a(n-9) +25*a(n-10) -495*a(n-11) +485*a(n-12) -44*a(n-13) -180*a(n-14) +554*a(n-15) -648*a(n-16) +14*a(n-17) +152*a(n-18) -190*a(n-19) -140*a(n-20) +397*a(n-21) -273*a(n-22) +75*a(n-23) +167*a(n-24) -136*a(n-25) +27*a(n-26) for n>28

%e Some solutions for n=4

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 03 2014