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A172695 Number of 5*n X 2*n 0..2 arrays with row sums 2 and column sums 5. 1
51, 79796556, 19292117692187340, 130096688857163908226867520, 10585995418849686886860491452609238400, 6309193293073551526242474424812731974830376454400 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..19

FORMULA

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

CROSSREFS

Sequence in context: A135531 A038777 A281979 * A172786 A324683 A214373

Adjacent sequences:  A172692 A172693 A172694 * A172696 A172697 A172698

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 06 2010

STATUS

approved

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Last modified January 29 05:09 EST 2022. Contains 350672 sequences. (Running on oeis4.)