A235656 - OEIS

%I #6 Jul 23 2025 08:42:22

%S 476,6378,85700,1088450,13349432,156257766,1760232169,19098030172,

%T 200821523820,2053582822620,20519104530695,201006081584245,

%U 1937283413026295,18420260232233213,173231193676166625

%N Number of (n+1)X(4+1) 0..1 arrays with the difference of the upper median and minimum value of each 2X2 subblock in lexicographically nondecreasing order rowwise and columnwise.

%C Column 4 of A235660

%H R. H. Hardin, <a href="/A235656/b235656.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=3

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 13 2014