A183410 - OEIS

%I #5 Mar 31 2012 12:35:51

%S 2,8,22,75,152,410,719,1632,2564,5130,7525,13720,19058,32359,43246,

%T 69423,89870,137872,174193,257432,318491,456159,554945,773911,927617,

%U 1264264,1496874,1999757,2341547,3073792,3565513,4608374,5299770,6755665,7711920

%N Number of nX3 binary arrays with each sum of a(1..i,1..j) no greater than i*j/2 and rows and columns in nondecreasing order

%C Column 3 of A183413

%H R. H. Hardin, <a href="/A183410/b183410.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n)=a(n-1)+2*a(n-4)-2*a(n-5)+a(n-6)-a(n-7)+3*a(n-8)-3*a(n-9)-2*a(n-10)+2*a(n-11)-8*a(n-12)+8*a(n-13)-3*a(n-14)+3*a(n-15)-2*a(n-16)+2*a(n-17)+8*a(n-18)-8*a(n-19)+12*a(n-20)-12*a(n-21)+2*a(n-22)-2*a(n-23)-2*a(n-24)+2*a(n-25)-12*a(n-26)+12*a(n-27)-8*a(n-28)+8*a(n-29)+2*a(n-30)-2*a(n-31)+3*a(n-32)-3*a(n-33)+8*a(n-34)-8*a(n-35)+2*a(n-36)-2*a(n-37)-3*a(n-38)+3*a(n-39)-a(n-40)+a(n-41)-2*a(n-42)+2*a(n-43)+a(n-46)-a(n-47)

%e Some solutions for 4X3

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Jan 04 2011