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A076793
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a(n) = Sum_{k=1..n} 2^prime(k).
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9
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0, 4, 12, 44, 172, 2220, 10412, 141484, 665772, 9054380, 545925292, 2693408940, 140132362412, 2339155617964, 11135248640172, 151872736995500, 9159071991736492, 585619824295159980, 2891462833508853932
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OFFSET
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0,2
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COMMENTS
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a(468) has 1000 decimal digits. - Michael De Vlieger, Jul 14 2017
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LINKS
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Michael De Vlieger, Table of n, a(n) for n = 0..467
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FORMULA
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a(n) = a(n-1) + 2^prime(n).
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EXAMPLE
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a(1) = 2^prime(1) = 2^2 = 4; a(2) = 4 + 2^prime(2) = 4 + 2^3 = 12.
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MATHEMATICA
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Table[Sum[2^Prime[k], {k, n}], {n, 0, 18}] (* Michael De Vlieger, Jul 14 2017 *)
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PROG
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(PARI) a(n) = sum(k=1, n, 2^prime(k)) \\ Michel Marcus, Jul 23 2013
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CROSSREFS
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Cf. A076794.
Sequence in context: A055542 A149365 A000759 * A007860 A226855 A039740
Adjacent sequences: A076790 A076791 A076792 * A076794 A076795 A076796
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KEYWORD
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easy,nonn
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AUTHOR
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Walter Carlini, Nov 17 2002
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EXTENSIONS
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More terms from R. J. Mathar, Aug 31 2007
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STATUS
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approved
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