

A176171


Second primefactor of nth product of 4 distinct primes.


2



3, 3, 3, 3, 3, 3, 3, 3, 3, 5, 3, 3, 3, 5, 3, 3, 3, 3, 5, 5, 3, 3, 3, 3, 3, 3, 5, 5, 3, 5, 3, 3, 3, 3, 5, 3, 3, 5, 3, 3, 3, 5, 3, 3, 3, 5, 7, 3, 5, 3, 5, 3, 5, 5, 3, 5, 3, 3, 3, 3, 5, 3, 3, 5, 3, 3, 5, 3, 5, 7, 3, 3, 3, 5, 3, 3, 5, 3, 3, 7, 3, 3, 5, 7, 5, 3, 5, 3, 3, 7, 3, 5, 3, 5, 3, 3, 5, 5, 3, 5, 3, 5, 3, 3, 3
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OFFSET

1,1


COMMENTS

FactorInteger[210]=2*3*5*7,...


LINKS

Table of n, a(n) for n=1..105.


MATHEMATICA

f0[n_]:=Last/@FactorInteger[n]=={1, 1, 1, 1}; f1[n_]:=Min[First/@FactorInteger[n]]; f2[n_]:=First/@FactorInteger[n][[2, 1]]; f3[n_]:=First/@FactorInteger[n][[3, 1]]; f4[n_]:=Max[First/@FactorInteger[n]]; lst={}; Do[If[f0[n], AppendTo[lst, f2[n]]], {n, 0, 2*7!}]; lst


CROSSREFS

Cf. A006881, A007304, A070647, A096916, A096917, A096918, A096919, A176170
Sequence in context: A135717 A335465 A079083 * A032568 A053388 A091786
Adjacent sequences: A176168 A176169 A176170 * A176172 A176173 A176174


KEYWORD

nonn


AUTHOR

Vladimir Joseph Stephan Orlovsky, Apr 10 2010


STATUS

approved



