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A060381 a(n) = prime(n)*prime(n+1)*...*prime(2*n-1), where prime(i) is the i-th prime. 3
1, 2, 15, 385, 17017, 1062347, 86822723, 10131543907, 1204461778591, 198229051666003, 35224440615606707, 6295457783127226289, 1331590860773071702483, 310692537866322378582047, 78832548083496383033878901, 21381953681344611984282084241 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Central terms of triangle A098012. - Reinhard Zumkeller, Oct 02 2014

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 0..250

FORMULA

a(n) = A002110(2*n-1)/A002110(n-1). - Michel Marcus, Mar 16 2019

EXAMPLE

a(1)=2; a(2) = 3*5 = 15; a(3) = 5*7*11 = 385.

MAPLE

seq(mul(ithprime(n+k), k=0..n-1), n=0..15); # Muniru A Asiru, Mar 16 2019

MATHEMATICA

Table[Times@@Prime[Range[n, 2n-1]], {n, 20}] (* Harvey P. Dale, Jul 19 2018 *)

PROG

(Haskell)

a060381 n = a098012 (2 * n - 1) n  -- Reinhard Zumkeller, Oct 02 2014

(GAP) P:=Filtered([1..200], IsPrime);;

a:=List([1..15], n->Product([0..n-1], k->P[n+k])); # Muniru A Asiru, Mar 16 2019

(PARI) a(n) = prod(k=n, 2*n-1, prime(k)); \\ Michel Marcus, Mar 16 2019

CROSSREFS

Cf. A002110, A098012.

Sequence in context: A254224 A071102 A272899 * A256369 A145328 A139810

Adjacent sequences:  A060378 A060379 A060380 * A060382 A060383 A060384

KEYWORD

easy,nonn

AUTHOR

Jason Earls, Apr 03 2001

EXTENSIONS

a(0)=1 prepended by Alois P. Heinz, Mar 16 2019

STATUS

approved

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Last modified October 22 07:29 EDT 2019. Contains 328315 sequences. (Running on oeis4.)