A236272 - OEIS

%I #6 Jul 23 2025 09:12:13

%S 208,1770,15434,137142,1226262,11005062,98896922,889370642,8000222410,

%T 71974995478,647568014134,5826408486934,52422934994538,

%U 471676295256450,4243925427421722,38184920729995814,343570793183657030

%N Number of (n+1)X(2+1) 0..2 arrays with the upper median unequal to the lower median in every 2X2 subblock.

%C Column 2 of A236278

%H R. H. Hardin, <a href="/A236272/b236272.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 11*a(n-1) -189*a(n-3) +169*a(n-4) +720*a(n-5) -498*a(n-6) -680*a(n-7) +48*a(n-8) +48*a(n-9)

%e Some solutions for n=4

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 21 2014