cp's OEIS Frontend

A241436 Number of 2Xn 0..3 arrays with no element equal to one 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 one plus the sum of the elements antidiagonally to its northeast, modulo 4.

%I A241436 #6 Jun 02 2025 10:09:05
%S A241436 3,5,10,21,45,88,181,378,710,1460,2973,5668,11567,23202,45182,91386,
%T A241436 182056,358886,721278,1433814,2843343,5691577,11312714,22494505,
%U A241436 44919750,89325211,177819368,354608529,705515901,1405063399,2799954077,5572860402
%N A241436 Number of 2Xn 0..3 arrays with no element equal to one 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 one plus the sum of the elements antidiagonally to its northeast, modulo 4.
%C A241436 Row 2 of A241435
%H A241436 R. H. Hardin, <a href="/A241436/b241436.txt">Table of n, a(n) for n = 1..210</a>
%F A241436 Empirical: a(n) = 2*a(n-2) +8*a(n-3) -a(n-4) -10*a(n-5) -18*a(n-6) +8*a(n-7) +20*a(n-8) +20*a(n-9) -24*a(n-10) -22*a(n-11) -a(n-12) +32*a(n-13) +8*a(n-14) -3*a(n-15) -12*a(n-16) +4*a(n-17) -5*a(n-18) -4*a(n-20) -3*a(n-21) +2*a(n-22) for n>24
%e A241436 Some solutions for n=4
%e A241436 ..3..3..2..2....3..2..3..3....3..3..2..2....3..3..2..3....3..3..2..2
%e A241436 ..3..2..1..0....2..2..3..2....2..1..2..0....2..1..1..3....3..2..0..0
%K A241436 nonn
%O A241436 1,1
%A A241436 _R. H. Hardin_, Apr 22 2014