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A086769 a(n) = sum{2^(b(i)-1): 1<=i<=n}, where b(n) is the differences between consecutive primes. 0
1, 3, 5, 13, 15, 23, 25, 33, 65, 67, 99, 107, 109, 117, 149, 181, 183, 215, 223, 225, 257, 265, 297, 425, 433, 435, 443, 445, 453, 8645, 8653, 8685, 8687, 9199, 9201, 9233, 9265, 9273, 9305, 9337, 9339, 9851, 9853, 9861, 9863, 11911, 13959, 13967, 13969 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..49.

FORMULA

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

EXAMPLE

2^(3-2)/2=1, so a(1)=1. 2^(5-3)/2=2, so a(2)=1+2=3.

PROG

(MATLAB) P = primes(500); l = length(P); S = P(2:l) - P(1:(l - 1)); A = cumsum(2.^(S-1))

CROSSREFS

Cf. A001223.

Sequence in context: A258976 A137162 A293863 * A018753 A073217 A063484

Adjacent sequences:  A086766 A086767 A086768 * A086770 A086771 A086772

KEYWORD

nonn,easy

AUTHOR

David G. Williams (davwill24(AT)aol.com), Aug 02 2003

EXTENSIONS

Edited by David Wasserman, Aug 28 2003

STATUS

approved

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Last modified October 17 18:58 EDT 2019. Contains 328127 sequences. (Running on oeis4.)