A063639 Primes of the form p*q*r - 1, where p, q and r are primes (not necessarily distinct).

7, 11, 17, 19, 29, 41, 43, 67, 97, 101, 109, 113, 137, 163, 173, 181, 211, 229, 241, 257, 281, 283, 317, 331, 337, 353, 373, 401, 409, 433, 523, 547, 577, 601, 617, 641, 653, 677, 691, 709, 761, 787, 821, 829, 853, 907, 937, 941, 977, 1009, 1021, 1033, 1051

Offset

1,1

Links

Harry J. Smith, Table of n, a(n) for n = 1..1000

Mathematica

Take[Select[Union[Times@@#-1&/@Tuples[Prime[Range[60]], 3]], PrimeQ], 60] (* Harvey P. Dale, Jan 23 2012 *)

Prog

(PARI) { n=0; for (m=1, 10^9, p=prime(m); if (bigomega(p + 1) == 3, write("b063639.txt", n++, " ", p); if (n==1000, break)) ) } \\ Harry J. Smith, Aug 26 2009
(Haskell)
a063639 n = a063639_list !! (n-1)
a063639_list = [p | p <- a000040_list, a001222 (p+1) == 3]
-- Reinhard Zumkeller, Feb 04 2012

Crossrefs

Cf. A014612, A063640.

Cf. A000040, A001222.

Sequence in context: A256567 A155048 A296926 * A230223 A309587 A339954

Adjacent sequences: A063636 A063637 A063638 * A063640 A063641 A063642

Keyword

nonn

Author

Reinhard Zumkeller, Jul 21 2001

Status

approved