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A174385 Product of 3 consecutive odd numbers n such that n+-2 are primes. 1
15, 105, 315, 79335, 148665, 300495, 1860375, 1952625, 3048045, 6538455, 14347935, 57065085, 82311135, 83451705, 169110165, 223646115, 335699595, 347426115, 410169435, 674522625, 736310715, 1015071105, 1655590755 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

All terms are divisible by 15. - Robert Israel, Apr 10 2018

LINKS

Robert Israel, Table of n, a(n) for n = 1..10000

EXAMPLE

1*3*5=15 and 15+2 and 15-2 are primes, so 15=a(1) is in the sequence.

3*5*7=105 and 105+2 and 105-2 are primes, so 105=a(2) is in the sequence.

MAPLE

select(t -> isprime(t+2) and isprime(t-2), [seq(n*(n+2)*(n+4), n=1..2000, 2)]); # Robert Israel, Apr 10 2018

MATHEMATICA

f[n_]:=n*(n+2)*(n+4); Select[Table[f[n], {n, 1, 7!, 2}], PrimeQ[ #-2]&&PrimeQ[ #+2]&]

Select[Times@@@Partition[Range[1, 1201, 2], 3, 1], AllTrue[#+{2, -2}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, May 17 2018 *)

CROSSREFS

Cf. A174383, A174384

Sequence in context: A102791 A160892 A061550 * A185129 A090454 A240440

Adjacent sequences:  A174382 A174383 A174384 * A174386 A174387 A174388

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Mar 17 2010

EXTENSIONS

Edited by Robert Israel, Apr 10 2018

STATUS

approved

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Last modified May 31 09:30 EDT 2020. Contains 334748 sequences. (Running on oeis4.)