A202029 - OEIS

%I #5 Mar 31 2012 12:36:46

%S 3,56,1341,29363,537572,8249505,108479344,1248911674,12812139620,

%T 118772002152,1006266126267,7863720278445,57120674129416,

%U 388168845356086,2481485055755353,14994743673623870,86001919259575522,469898358909610160

%N Number of nX4 zero-sum -1..1 arrays with rows and columns lexicographically nondecreasing

%C Column 4 of A202033

%H R. H. Hardin, <a href="/A202029/b202029.txt">Table of n, a(n) for n = 1..111</a>

%e Some solutions for n=4

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_ Dec 09 2011