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A085530
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a(n) = (2n+1)^(2n).
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4
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1, 9, 625, 117649, 43046721, 25937424601, 23298085122481, 29192926025390625, 48661191875666868481, 104127350297911241532841, 278218429446951548637196401, 907846434775996175406740561329, 3552713678800500929355621337890625, 16423203268260658146231467800709255289
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OFFSET
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0,2
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COMMENTS
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a(n)/4^n is the square of the determinant of a (2*n+1) X (2*n+1) matrix with elements M(j,k) = cos(Pi*j*k/n). See the MathOverflow link. - Hugo Pfoertner, Sep 18 2021
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LINKS
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FORMULA
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(End)
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MATHEMATICA
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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