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A185297 Consider all pairs of primes (p,q) with p+q = 2n, p <= q; a(n) is the sum of all the p's. 7
2, 3, 3, 8, 5, 10, 8, 12, 10, 19, 23, 23, 16, 31, 16, 36, 42, 26, 31, 48, 23, 48, 59, 42, 39, 71, 35, 62, 108, 53, 59, 96, 38, 83, 108, 91, 77, 127, 76, 107, 178, 85, 92, 217, 66, 127, 169, 87, 148, 204, 121, 148, 196, 134, 165, 268, 122, 168, 358, 136, 145, 340, 111, 219, 323, 206, 157, 282, 255, 272, 373, 246, 175, 486, 132, 260, 419 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..78.

EXAMPLE

2*5 = 10 can be expressed as the sum of two primes in two ways, 3+7 and 5+5, so a(5) = 3+5 = 8.

MAPLE

with(numtheory);

a:=n-> sum( (i)*( ((pi(i) - pi(i-1)) * (pi(2*n-i) - pi(2*n-i-1))) ), i = 1..n ); seq(a(k), k=1..100); # Wesley Ivan Hurt, Jan 20 2013

CROSSREFS

Cf. A045917, A187129, A186201.

Sequence in context: A078035 A295725 A132822 * A202818 A256679 A193997

Adjacent sequences:  A185294 A185295 A185296 * A185298 A185299 A185300

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Mar 11 2011

STATUS

approved

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Last modified July 20 01:17 EDT 2019. Contains 325168 sequences. (Running on oeis4.)