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

1,1

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

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 *)

Crossrefs

Cf. A173966, A173967, A173968

Sequence in context: A202052 A284450 A173968 * A140062 A203407 A204867

Adjacent sequences: A173966 A173967 A173968 * A173970 A173971 A173972

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, Mar 03 2010

Extensions

Definition clarified by Harvey P. Dale, Aug 14 2021

Status

approved