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A236809 T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the lower median minus the upper median minus the minimum of every 2X2 subblock equal.

%I A236809 #6 Jul 23 2025 09:34:47
%S A236809 81,277,277,1033,1435,1033,4183,8825,8825,4183,17481,60187,85929,
%T A236809 60187,17481,75907,410305,929447,929447,410305,75907,330433,2926867,
%U A236809 9558409,16530709,9558409,2926867,330433,1468723,20377961,107087939,270610375
%N A236809 T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with the maximum plus the lower median minus the upper median minus the minimum of every 2X2 subblock equal.
%C A236809 Table starts
%C A236809 .......81........277..........1033............4183..............17481
%C A236809 ......277.......1435..........8825...........60187.............410305
%C A236809 .....1033.......8825.........85929..........929447............9558409
%C A236809 .....4183......60187........929447........16530709..........270610375
%C A236809 ....17481.....410305.......9558409.......270610375.........6612746409
%C A236809 ....75907....2926867.....107087939......5140896385.......203606804707
%C A236809 ...330433...20377961....1117775361.....86863046591......5094225962785
%C A236809 ..1468723..147734251...12821027315...1730194335025....167431587932179
%C A236809 ..6479721.1039350577..135199336873..29809824906343...4238424064205001
%C A236809 .29026267.7613312515.1580326999835.613527734331097.146743496294875195
%H A236809 R. H. Hardin, <a href="/A236809/b236809.txt">Table of n, a(n) for n = 1..180</a>
%F A236809 Empirical for column k:
%F A236809 k=1: a(n) = 5*a(n-1) +20*a(n-2) -130*a(n-3) +36*a(n-4) +600*a(n-5) -720*a(n-6)
%F A236809 k=2: [order 10]
%F A236809 k=3: [order 11]
%F A236809 k=4: [order 13]
%F A236809 k=5: [order 13]
%F A236809 k=6: [order 17]
%F A236809 k=7: [order 16]
%e A236809 Some solutions for n=3 k=4
%e A236809 ..0..0..2..2..2....0..0..2..2..2....0..0..1..1..2....0..0..2..2..1
%e A236809 ..0..1..2..1..0....1..2..1..0..1....0..1..1..0..0....1..2..1..0..2
%e A236809 ..2..0..2..2..0....0..0..2..2..0....1..1..2..2..1....2..0..2..2..1
%e A236809 ..1..2..1..0..1....2..1..2..1..2....2..1..1..2..0....1..0..1..2..2
%K A236809 nonn,tabl
%O A236809 1,1
%A A236809 _R. H. Hardin_, Jan 31 2014