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A076793 a(n) = Sum_{k=1..n} 2^prime(k). 9
0, 4, 12, 44, 172, 2220, 10412, 141484, 665772, 9054380, 545925292, 2693408940, 140132362412, 2339155617964, 11135248640172, 151872736995500, 9159071991736492, 585619824295159980, 2891462833508853932 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

a(468) has 1000 decimal digits. - Michael De Vlieger, Jul 14 2017

LINKS

Michael De Vlieger, Table of n, a(n) for n = 0..467

FORMULA

a(n) = a(n-1) + 2^prime(n).

EXAMPLE

a(1) = 2^prime(1) = 2^2 = 4; a(2) = 4 + 2^prime(2) = 4 + 2^3 = 12.

MATHEMATICA

Table[Sum[2^Prime[k], {k, n}], {n, 0, 18}] (* Michael De Vlieger, Jul 14 2017 *)

PROG

(PARI) a(n) = sum(k=1, n, 2^prime(k)) \\ Michel Marcus, Jul 23 2013

CROSSREFS

Cf. A076794.

Sequence in context: A055542 A149365 A000759 * A007860 A226855 A039740

Adjacent sequences:  A076790 A076791 A076792 * A076794 A076795 A076796

KEYWORD

easy,nonn

AUTHOR

Walter Carlini, Nov 17 2002

EXTENSIONS

More terms from R. J. Mathar, Aug 31 2007

STATUS

approved

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Last modified May 29 07:49 EDT 2022. Contains 354122 sequences. (Running on oeis4.)