A174383 Product of two consecutive odd numbers n such that n+-2 are primes.

15, 99, 195, 399, 675, 1599, 12099, 15375, 21315, 42435, 62499, 106275, 115599, 122499, 190095, 193599, 220899, 401955, 470595, 495615, 846399, 1008015, 1110915, 1123599, 1263375, 1336335, 1552515, 1628175, 1674435, 1731855

Offset

1,1

Comments

3*5 = 15+-2 -> primes, 9*11 = 99+-2 -> primes,..

Links

Table of n, a(n) for n=1..30.

Mathematica

f[n_]:=n*(n+2); Select[Table[f[n], {n, 1, 7!, 2}], PrimeQ[ #-2]&&PrimeQ[ #+2]&]
Select[Times@@@Partition[Range[1, 2001, 2], 2, 1], And@@PrimeQ[#+{2, -2}]&] (* Harvey P. Dale, Dec 14 2012 *)

Crossrefs

Sequence in context: A159528 A108681 A108254 * A341396 A307158 A000973

Adjacent sequences: A174380 A174381 A174382 * A174384 A174385 A174386

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Mar 17 2010

Status

approved