cp's OEIS Frontend

A200559 Number of -n..n arrays x(0..8) of 9 elements with zero sum and nonzero second differences.

%I A200559 #7 Jul 22 2025 15:52:45
%S A200559 778,91058,1639804,13587804,72366820,288237528,936121220,2613794508,
%T A200559 6492378076,14694189538,30833955936,60757353766,113535692414,
%U A200559 202761648044,348183768616,577776075892,930286238568,1458297755836
%N A200559 Number of -n..n arrays x(0..8) of 9 elements with zero sum and nonzero second differences.
%C A200559 Row 7 of A200553
%H A200559 R. H. Hardin, <a href="/A200559/b200559.txt">Table of n, a(n) for n = 1..39</a>
%e A200559 Some solutions for n=3
%e A200559 .-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3...-3
%e A200559 .-3....1...-3....1....0....1....0....0....0....1...-3....1....1....1....0....1
%e A200559 ..3....3...-1....2....2....2....1...-3...-3....0...-1...-1...-2....3...-1....1
%e A200559 ..0....3....3....1....0....1...-1....3....2...-3....2...-1....3....2....1....2
%e A200559 ..3....0...-2....2...-3...-1....3....1....1....0....3....3....2....0....2....0
%e A200559 ..0...-2....3...-3...-3...-2...-2....3...-1....1....0....1...-3....1....2...-3
%e A200559 ..2....0....2....2....3....3....2...-1....3....1....1....3...-2...-2...-1....1
%e A200559 .-2....1....0...-1....2...-3....1...-2....2....3....3...-2....3...-3...-2...-2
%e A200559 ..0...-3....1...-1....2....2...-1....2...-1....0...-2...-1....1....1....2....3
%K A200559 nonn
%O A200559 1,1
%A A200559 _R. H. Hardin_ Nov 19 2011