A173969 Sums of three consecutive numbers each of which is the product of two distinct primes and each of which has no exponent greater than one for either of its two prime factors.

102, 258, 282, 426, 606, 642, 654, 906, 1182, 1338, 1902, 2094, 2766, 3126, 3414, 3786, 4038, 4206, 4926, 5286, 5514, 5682, 5826, 5946, 6306, 6546, 6654, 6918, 7086, 7302, 7386, 7554, 7926, 8166, 8202, 9294, 10158, 10806, 11082, 11598, 11706, 11874

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Mar 03 2010

Keywords

• nonn

Comments

Terms that included in A173968 but Not included in the current seq are: 366,2526,18726,220326,430926,637566,814326,..

The number of prime factors of each of the 3 consecutive numbers must be 2 even when counted with multiplicity. - Harvey P. Dale, Aug 14 2021

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A173966, A173967, A173968

Programs

Mathematica

f[n_]:=Last/@FactorInteger[n]=={1,1};lst={};Do[If[f[n],If[f[n+1]&&f[n+2],AppendTo[lst,3*n+3]]],{n,8!}];lst2=lst
Total[#]+Mean[#]&/@SequencePosition[Table[If[PrimeNu[n]==PrimeOmega[n]==2,1,0],{n,4000}],{1,1,1}] (* Harvey P. Dale, Aug 14 2021 *)

Extensions

Definition clarified by Harvey P. Dale, Aug 14 2021