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A117495 Product of a prime number p and the number of primes smaller than p. 4
0, 3, 10, 21, 44, 65, 102, 133, 184, 261, 310, 407, 492, 559, 658, 795, 944, 1037, 1206, 1349, 1460, 1659, 1826, 2047, 2328, 2525, 2678, 2889, 3052, 3277, 3810, 4061, 4384, 4587, 5066, 5285, 5652, 6031, 6346, 6747, 7160, 7421, 8022, 8299, 8668, 8955, 9706 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Jens Kruse Andersen, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = (n-1)*prime(n). - Zak Seidov, Aug 15 2010

EXAMPLE

a(9) = 184 because (1) the 9th prime number is 23, (2) there are 8 primes smaller than 23 and (3) 23*8 = 184.

MAPLE

with(numtheory):a:=n->sum(ithprime(n), j=2..n):seq(a(n), n=1..47); # Zerinvary Lajos, Aug 24 2008

MATHEMATICA

Table[(n - 1)Prime[n], {n, 60}] (* Zak Seidov, Aug 15 2010 *)

PROG

(PARI) a(n)=prime(n)*(n-1) \\ Charles R Greathouse IV, Sep 15 2014

CROSSREFS

Cf. A000720, A033286, A036689.

Sequence in context: A210980 A207380 A268348 * A007687 A192033 A295063

Adjacent sequences:  A117492 A117493 A117494 * A117496 A117497 A117498

KEYWORD

nonn,easy

AUTHOR

Luc Stevens (lms022(AT)yahoo.com), Apr 25 2006

EXTENSIONS

a(31) corrected by Jens Kruse Andersen, Sep 15 2014

STATUS

approved

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Last modified November 21 05:01 EST 2017. Contains 294988 sequences.