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A117495 Product of a prime number p and the number of primes smaller than p. 5
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
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
Sequence in context: A210980 A207380 A268348 * A007687 A330273 A335666
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 March 29 06:15 EDT 2024. Contains 371265 sequences. (Running on oeis4.)