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A014491
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a(n) = gcd(n, 2^n - 1).
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8
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1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 9, 1, 5, 7, 1, 1, 3, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 9, 1, 1, 1, 5, 1, 21, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 27, 1, 1, 1, 1, 1, 15, 1, 1, 7, 1, 1, 3, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 3, 1, 5, 1, 1, 1, 21, 1, 1, 1, 1, 1, 9, 1, 1, 1, 1, 1, 3, 1, 1
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OFFSET
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1,6
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COMMENTS
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Also the GCD of the "binary n-th powers", the set of positive integers whose base-2 representation consists of a block of bits repeated n times consecutively. - Jeffrey Shallit, Jan 16 2018
prime(k) for k >= 2 divides a(n) if and only if n is divisible by prime(k)*A014664(k). - Robert Israel, Jan 16 2018
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LINKS
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MAPLE
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MATHEMATICA
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CROSSREFS
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KEYWORD
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nonn,easy,nice
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AUTHOR
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Gary M. Mcguire (gmm8n(AT)weyl.math.virginia.edu)
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STATUS
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approved
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