A168477 Numbers that are the product of two distinct primes and they are sum of two consecutive products of two distinct primes.

69, 77, 85, 106, 115, 134, 143, 159, 178, 187, 201, 217, 226, 237, 262, 267, 291, 301, 327, 355, 381, 395, 403, 411, 415, 422, 427, 437, 447, 502, 527, 565, 586, 597, 614, 623, 633, 649, 669, 674, 687, 713, 758, 763, 789, 793, 818, 849, 893, 898, 951, 959

Offset

1,1

Links

Table of n, a(n) for n=1..52.

Example

6,10,14,15,21,22,26,33,34,35,38,39,46,..A006881 Numbers that are the product of two distinct primes 69=34+35, 77=38+39, 85=39+46,.. 69=3*13, 77=7*11, 85=5*13,..

Mathematica

f[n_]:=Last/@FactorInteger[n]=={1, 1}; a=6; lst={}; Do[If[f[n], p=a+n; If[f[p], AppendTo[lst, p]]; a=n], {n, 9, 7!}]; lst

Crossrefs

Cf. A006881, A168474

Sequence in context: A253437 A325386 A260428 * A264045 A295806 A210614

Adjacent sequences: A168474 A168475 A168476 * A168478 A168479 A168480

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Nov 26 2009

Status

approved