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A172695 Number of 5*n X 2*n 0..2 arrays with row sums 2 and column sums 5. 1

%I

%S 51,79796556,19292117692187340,130096688857163908226867520,

%T 10585995418849686886860491452609238400,

%U 6309193293073551526242474424812731974830376454400

%N Number of 5*n X 2*n 0..2 arrays with row sums 2 and column sums 5.

%H R. H. Hardin, <a href="/A172695/b172695.txt">Table of n, a(n) for n = 1..19</a>

%F a(n) = 120^(-2n)*(2n)!(5n)!*Sum_{i=0..2n} Sum_{j=0..2n-i} (10^j*15^(2n-i-j)*(4i+2j+2n)!/(i!j!(2n-i-j)!(n+j+2i)!2^(n+j+2i))). - _Shanzhen Gao_, Feb 24 2010

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 06 2010

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Last modified May 23 09:39 EDT 2022. Contains 353975 sequences. (Running on oeis4.)