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A005017
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Denominator of (binomial(2*n-2,n-1)/n!)^2.
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5
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1, 1, 1, 36, 144, 400, 3600, 2822400, 16257024, 32920473600, 823011840000, 8129341440000, 292656291840000, 3877578804363264, 58642395498086400, 844450495172444160000, 54044831691036426240000, 1161740555606493757440000, 76817130615613056614400
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OFFSET
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1,4
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LINKS
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FORMULA
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MATHEMATICA
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Denominator[Table[(Binomial[2n-2, n-1]/n!)^2, {n, 20}]] (* Harvey P. Dale, May 30 2012 *)
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PROG
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(PARI) a(n) = denominator((binomial(2*n-2, n-1)/n!)^2); \\ Michel Marcus, Jul 14 2022
(Magma) [Denominator((Catalan(n-1)/Factorial(n-1))^2): n in [1..40]]; // G. C. Greubel, Sep 12 2023
(SageMath) [denominator((catalan_number(n-1)/factorial(n-1))^2) for n in range(1, 41)] # G. C. Greubel, Sep 12 2023
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CROSSREFS
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KEYWORD
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nonn,frac
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AUTHOR
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STATUS
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approved
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