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A260982
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a(n) = (2^(2^(n+1)) + 2^(2^n) + 1)/21.
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0
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OFFSET
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1,2
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LINKS
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Table of n, a(n) for n=1..7.
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FORMULA
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a(n) = A001576(2^n)/21. - Michel Marcus, Aug 14 2015
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EXAMPLE
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a(2) = (2^(2^(2+1)) + 2^(2^2) + 1)/21 = 13.
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MATHEMATICA
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Table[(2^(2^(n + 1)) + 2^(2^n) + 1)/21, {n, 1, 10}] (* Vincenzo Librandi, Aug 08 2015 *)
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PROG
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(PARI) first(m)=my(v=vector(m, t, (2^(2^(t+1))+2^(2^t)+1)/21)); v; /* Anders Hellström, Aug 07 2015 */
(MAGMA) [(2^(2^(n+1)) + 2^(2^n) + 1)/21: n in [1..10]]; // Vincenzo Librandi, Aug 08 2015
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CROSSREFS
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Cf. A001576 (1^n + 2^n + 4^n).
Sequence in context: A208315 A296174 A220642 * A159357 A221885 A134159
Adjacent sequences: A260979 A260980 A260981 * A260983 A260984 A260985
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KEYWORD
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nonn,easy
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AUTHOR
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Marco Ripà, Aug 07 2015
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STATUS
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approved
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