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%I #4 Mar 31 2012 12:35:26
%S 1,4,9,25,49,121,225,483,892,1726,2999,5517,9136,15691,25423,41668,
%T 64943,102972,155880,238808,353814,525710,760658,1106657,1568464,
%U 2228879,3108245,4333985,5940271,8151896,11007043,14867782,19823198,26397150
%N Number of nondecreasing integer sequences of length 15 with sum zero and sum of absolute values 2n.
%C a(n) = A000041(n)^2 for n<=7
%C a(n) = A000041(n)^2 - cumulative A000712(2*n-1-length), 0 <= 2*n-1-length <= floor(n/2) [empirical].
%H R. H. Hardin, <a href="/A158149/b158149.txt">Table of n, a(n) for n=1..405</a>
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 13 2009