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%I #18 Jan 23 2018 07:01:56
%S 1,842090474940,9561215418596022668009737500,
%T 41499275921837441873503310658937755719615400000,
%U 15806556884633733578544972910460376919497070823113887278535399000000
%N Number of 9*n X 2*n 0..1 arrays with row sums 2 and column sums 9.
%D Gao, Shanzhen, and Matheis, Kenneth, Closed formulas and integer sequences arising from the enumeration of (0,1)-matrices with row sum two and some constant column sums. In Proceedings of the Forty-First Southeastern International Conference on Combinatorics, Graph Theory and Computing. Congr. Numer. 202 (2010), 45-53.
%H R. H. Hardin, <a href="/A172616/b172616.txt">Table of n, a(n) for n = 1..11</a>
%K nonn
%O 1,2
%A _R. H. Hardin_, Feb 06 2010
%E Incorrect formula removed by _Jon E. Schoenfield_, Jan 22 2018
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