A091376 Numbers k with property that the number of prime factors of k (counted with repetition) equals the smallest prime factor of k.

4, 6, 10, 14, 22, 26, 27, 34, 38, 45, 46, 58, 62, 63, 74, 75, 82, 86, 94, 99, 105, 106, 117, 118, 122, 134, 142, 146, 147, 153, 158, 165, 166, 171, 178, 194, 195, 202, 206, 207, 214, 218, 226, 231, 254, 255, 261, 262, 273, 274, 278, 279, 285, 298, 302, 314

Offset

1,1

Comments

A091371(a(n)) = 0: A001222(a(n))=A020639(a(n)).

Prime factors counted with multiplicity. - Harvey P. Dale, Nov 11 2012

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Mathematica

pfQ[n_]:=Module[{fi=Transpose[FactorInteger[n]]}, fi[[1, 1]] == Total[Last[fi]]]; Rest[Select[Range[400], pfQ]] (* Harvey P. Dale, Nov 11 2012 *)
Select[Range[400], PrimeOmega[#]==FactorInteger[#][[1, 1]]&] (* Harvey P. Dale, Nov 26 2024 *)

Prog

(Haskell)
a091376 n = a091376_list !! (n-1)
a091376_list = [x | x <- a002808_list, a001222 x == a020639 x]
-- Reinhard Zumkeller, Nov 11 2012

Crossrefs

Cf. A091373, A091375, A091377.

Cf. A002808.

Cf. A100484 (subsequence).

Sequence in context: A137860 A184335 A243428 * A363134 A100484 A076924

Adjacent sequences: A091373 A091374 A091375 * A091377 A091378 A091379

Keyword

nonn

Author

Reinhard Zumkeller, Jan 04 2004

Extensions

Definition edited by N. J. A. Sloane, Jan 21 2020

Status

approved