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A239995 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.

%I A239995 #6 Jun 02 2025 09:36:56
%S A239995 3,13,61,256,1117,5012,22592,102336,465662,2123857,9698188,44317651,
%T A239995 202610817,926532786,4237612923,19382872561,88661747469,405570672096,
%U A239995 1855255219753,8486814865920,38822908166872,177595801954595
%N A239995 Number of nX2 0..3 arrays with no element equal to one plus the sum of elements to its left or two plus the sum of elements above it or one plus the sum of the elements diagonally to its northwest, modulo 4.
%C A239995 Column 2 of A240000
%H A239995 R. H. Hardin, <a href="/A239995/b239995.txt">Table of n, a(n) for n = 1..210</a>
%F A239995 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)
%e A239995 Some solutions for n=5
%e A239995 ..3..3....0..3....0..3....3..3....3..3....3..3....3..3....0..0....0..3....3..3
%e A239995 ..0..3....3..2....0..0....0..2....0..3....0..3....0..3....3..3....0..2....0..3
%e A239995 ..0..3....2..1....3..3....0..0....2..2....0..3....3..2....3..3....3..2....3..3
%e A239995 ..2..2....2..1....0..2....3..2....2..1....3..2....3..1....2..2....2..2....2..1
%e A239995 ..2..0....2..0....2..0....3..2....2..0....3..3....2..1....3..1....0..0....3..1
%K A239995 nonn
%O A239995 1,1
%A A239995 _R. H. Hardin_, Mar 30 2014