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%I #5 Mar 31 2012 12:36:11
%S 1,4,4,10,10,20,22,37,45,68,88,122,160,214,276,359,451,574,704,880,
%T 1066,1310,1572,1899,2257,2682,3158,3710,4328,5038,5824,6725,7707,
%U 8834,10054,11444,12948,14640,16476,18511,20729,23166,25818,28718,31860,35290,38980
%N Number of nondecreasing strings of numbers x(i=1..n) in -3..3 with sum x(i)^3 equal to 0
%C Column 3 of A188277
%H R. H. Hardin, <a href="/A188271/b188271.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n)=a(n-1)+2*a(n-2)-2*a(n-3)-a(n-4)+a(n-5)+a(n-9)-a(n-10)-2*a(n-11)+2*a(n-12)+a(n-13)-a(n-14)+a(n-28)-a(n-29)-2*a(n-30)+2*a(n-31)+a(n-32)-a(n-33)+a(n-35)-a(n-36)-3*a(n-37)+3*a(n-38)+3*a(n-39)-3*a(n-40)-a(n-41)+a(n-42)-a(n-44)+a(n-45)+2*a(n-46)-2*a(n-47)-a(n-48)+a(n-49)-a(n-63)+a(n-64)+2*a(n-65)-2*a(n-66)-a(n-67)+a(n-68)+a(n-72)-a(n-73)-2*a(n-74)+2*a(n-75)+a(n-76)-a(n-77)
%e Some solutions for n=8 k=3
%e .-1...-1....0...-3...-3...-2...-2...-3...-2...-1...-3...-3...-3...-2...-1...-3
%e .-1...-1....0...-3...-3....0...-1...-3...-2....0...-3...-3....0...-2...-1...-3
%e .-1...-1....0...-2...-2....0...-1...-3....0....0...-3...-3....1...-2....0...-3
%e ..0...-1....0...-2...-1....0...-1...-1....0....0....0...-3....1...-1....0...-2
%e ..0....1....0....2....1....0....1....1....0....0....0....3....1...-1....0....2
%e ..1....1....0....2....2....0....1....3....0....0....3....3....2...-1....0....3
%e ..1....1....0....3....3....0....1....3....2....0....3....3....2....0....1....3
%e ..1....1....0....3....3....2....2....3....2....1....3....3....2....3....1....3
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 26 2011
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