A096918 Intermediate prime factor of n-th product of 3 distinct primes.

3, 3, 3, 5, 3, 3, 5, 5, 3, 5, 3, 7, 5, 5, 3, 7, 3, 5, 5, 3, 5, 7, 7, 3, 5, 3, 7, 7, 3, 5, 11, 5, 5, 3, 7, 5, 3, 7, 3, 5, 11, 7, 7, 3, 7, 5, 11, 3, 11, 5, 7, 5, 3, 13, 7, 5, 5, 3, 7, 13, 3, 11, 7, 5, 3, 5, 11, 7, 3, 5, 7, 13, 7, 3, 7, 5, 5, 3, 11, 11, 3, 5, 17, 7, 3, 7, 13, 7, 5, 3, 11, 5, 5, 11, 5

Offset

1,1

Comments

A096917(n)*a(n)*A096919(n) = A007304(n); A096917(n) < a(n) < A096919(n).

Links

Table of n, a(n) for n=1..95.

Mathematica

f[n_]:=Last/@FactorInteger[n]=={1, 1, 1}; f1[n_]:=Min[First/@FactorInteger[n]]; f2[n_]:=Max[First/@FactorInteger[n]]; f3[n_]:=First/@FactorInteger[n][[2, 1]]; lst={}; Do[If[f[n], AppendTo[lst, f3[n]]], {n, 0, 7!}]; lst (* Vladimir Joseph Stephan Orlovsky, Apr 10 2010 *)

Crossrefs

Sequence in context: A162022 A318240 A262289 * A075018 A324974 A125958

Adjacent sequences: A096915 A096916 A096917 * A096919 A096920 A096921

Keyword

nonn

Author

Reinhard Zumkeller, Jul 15 2004

Status

approved