A168476 Numbers that are the product of two distinct primes and they are partial sum of products of two distinct primes.

6, 254, 339, 445, 502, 622, 687, 989, 1247, 1726, 1837, 2189, 2434, 2563, 3113, 3401, 4701, 5069, 5853, 6261, 6467, 7318, 8193, 8654, 8891, 10415, 11499, 12077, 14803, 15122, 15766, 19883, 25385, 26639, 27503, 28394, 28841, 33977, 34462, 34951

Offset

1,1

Links

Table of n, a(n) for n=1..40.

Example

6,10,14,15,21,22,26,33,34,35,38,39,46,..A006881 Numbers that are the product of two distinct primes 6,16,30,45,66,88,114,147,181,216,254,...A168472 Partial sums of products of two distinct primes 6=2*3, 254=2*127, 339=3*113, 445=5*89,..

Mathematica

f[n_]:=Last/@FactorInteger[n]=={1, 1}; s=0; lst={}; Do[If[f[n], If[f[s+=n], AppendTo[lst, s]]], {n, 6!}]; lst
Module[{tdp=Subsets[Prime[Range[2000]], {2}], pr}, pr=Times@@@tdp; Take[ Intersection[ pr, Accumulate[Sort[pr]]], 40]] (* Harvey P. Dale, Oct 15 2015 *)

Crossrefs

Cf. A006881, A168472

Sequence in context: A230881 A332563 A041853 * A320979 A279869 A271501

Adjacent sequences: A168473 A168474 A168475 * A168477 A168478 A168479

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Nov 26 2009

Status

approved