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A067563 Product of n-th prime number and n-th composite number. 4
8, 18, 40, 63, 110, 156, 238, 285, 368, 522, 620, 777, 902, 1032, 1175, 1378, 1593, 1708, 2010, 2272, 2409, 2686, 2905, 3204, 3686, 3939, 4120, 4494, 4796, 5085, 5842, 6288, 6713, 6950, 7599, 7852, 8478, 8965, 9352, 9861, 10382, 10860, 11842, 12159 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = prime(n) * composite(n).

EXAMPLE

E.g. a(4)=63 because the fourth prime is 7 and the fourth composite is 9.

MATHEMATICA

Module[{nn=50, prs, comps, len}, prs=Prime[Range[nn]]; comps=Complement[ Range[ 4, 3nn], prs]; len=Min[nn, Length[comps]]; Times@@@Thread[ {Take[ prs, len], Take[comps, len]}]](* Harvey P. Dale, Sep 02 2015 *)

PROG

Haskell)

a067563 n = a000040 n * a002808 n  -- Reinhard Zumkeller, Apr 30 2014

(Python)

from sympy import prime, composite

def A067563(n):

    return prime(n)*composite(n) # Chai Wah Wu, Dec 27 2018

CROSSREFS

Cf. A000040, A002808, A064799.

Cf. A127118, A038529.

Sequence in context: A082227 A134062 A251251 * A211477 A123134 A096283

Adjacent sequences:  A067560 A067561 A067562 * A067564 A067565 A067566

KEYWORD

easy,nonn

AUTHOR

Rick L. Shepherd, Jan 29 2002

STATUS

approved

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Last modified August 22 05:00 EDT 2019. Contains 326172 sequences. (Running on oeis4.)