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A120307
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Inverse determinant of n X n matrix M[i,j] = i*j/(i+j-1).
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1
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OFFSET
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1,2
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LINKS
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FORMULA
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a(n) = 1/Det[ Table[ i*j/(i+j-1), {i, n}, {j, n}]]. a(n+1)/a(n) = A000891[n] = (2n)!(2n+1)! / (n! (n+1)!)^2 = (2n+1)*CatalanNumber[n]^2 = (2n+1)*A000108[n]^2 = C(2n+1,n+1)*CatalanNumber[n] = A001700[n]*A000108[n].
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MATHEMATICA
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Table[ 1/Det[ Table[ i*j/(i+j-1), {i, n}, {j, n}]], {n, 1, 12}]
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PROG
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(Sage)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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