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A127200 Numerator of n-th partial sum of the Van der Waerden-Ulam binary measure of the primes. 1
1, 1, 5, 23, 49, 51, 13, 105, 211, 1693, 3391, 1697, 6791, 13585, 27173, 108699, 217405, 217409, 217411, 54353, 434825, 6957209, 13914427, 27828863, 55657735, 111315479, 222630967, 55657743, 445261949, 1781047807, 3562095625 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,3

LINKS

Table of n, a(n) for n=2..32.

MATHEMATICA

Table[Numerator[Sum[PrimePi[k]/2^k, {k, 2, x}]], {x, 2, 100}]

PROG

(PARI) a(n) = numerator(sum(k=2, n, primepi(k)/2^k)); \\ Michel Marcus, Oct 28 2019

CROSSREFS

Cf. A119523, A127197, A127201.

Sequence in context: A031387 A057622 A055626 * A147113 A135771 A327409

Adjacent sequences:  A127197 A127198 A127199 * A127201 A127202 A127203

KEYWORD

nonn,frac

AUTHOR

Artur Jasinski, Jan 08 2007

STATUS

approved

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Last modified April 5 16:43 EDT 2020. Contains 333245 sequences. (Running on oeis4.)