%I A079486
%S A079486 3,15,103,879,8787,99061,1227369,16409937,233588249,3504149013,
%T A079486 54963273921,895797910129
%N A079486 Number of different solutions to a variant of the 3-ball tennis ball 
               problem.
%C A079486 You're given labeled balls three at time (labeled 1,2,3 then 4,5,6 etc.), 
               choose two balls from those still on hand (including the three you've 
               just been given) and throw the larger out the window onto the front 
               lawn, the smaller onto the back lawn.
%D A079486 Larger numbers computed by Matt Richey.
%F A079486 a(n) is the number of 2 X n matrices of positive integers, with the numbers 
               in each row and column increasing, the numbers in column k less than 
               or equal to 3k and no number used more than once.
%Y A079486 Cf. A000108, A001764, A002293, A049235.
%Y A079486 Sequence in context: A109777 A135903 A123184 this_sequence A001274 A139766 
               A003276
%Y A079486 Adjacent sequences: A079483 A079484 A079485 this_sequence A079487 A079488 
               A079489
%K A079486 nonn
%O A079486 1,1
%A A079486 Barry Cipra (bcipra(AT)rconnect.com), Jan 19 2003