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A261067
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a(n) = (11^(2^n) - 1)/2^(n + 2).
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1
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OFFSET
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1,1
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COMMENTS
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(m^(2^n) - 1)/2^(n + 2) is an integer for any odd value of m and n > 0.
In particular, for m = 11, a(n) is a multiple of 15.
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LINKS
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FORMULA
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EXAMPLE
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a(3) = (11^8 - 1)/2^5 = 6698715.
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MAPLE
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MATHEMATICA
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PROG
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(PARI) first(m)=vector(m, i, (11^(2^i)-1)/2^(i+2)); /* Anders Hellström, Aug 08 2015 */
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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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