A119956 Numbers n such that n^3+1=p*q*r where p,q,r are distinct primes.

9, 10, 12, 13, 21, 25, 30, 34, 36, 40, 46, 52, 66, 76, 81, 90, 96, 118, 126, 130, 132, 142, 144, 154, 165, 172, 177, 180, 193, 196, 198, 204, 216, 226, 228, 238, 240, 246, 250, 256, 262, 268, 273, 282, 294, 312, 333, 336, 345, 346, 366, 370, 372, 378, 393, 400

Offset

1,1

Comments

A115403 is a supersequence not requiring that p,q,r are distinct.

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Example

9^3+1=2*5*73 a product of 3 distinct primes, so 9 is in the sequence.

Mathematica

Select[Range[400], Last/@FactorInteger[#^3 + 1] == {1, 1, 1}&] (* Vincenzo Librandi, Sep 15 2016 *)

Crossrefs

Cf. A115403.

Sequence in context: A202706 A104627 A188057 * A059102 A295743 A356659

Adjacent sequences: A119953 A119954 A119955 * A119957 A119958 A119959

Keyword

nonn

Author

James R. Buddenhagen, Aug 02 2006

Status

approved