A242034 a(n)=lpf(A243937(n)-3), where lpf = least prime factor (A020639).

3, 5, 3, 11, 3, 17, 3, 3, 29, 3, 5, 3, 41, 3, 3, 3, 59, 3, 5, 3, 71, 3, 7, 3, 3, 3, 5, 3, 101, 3, 107, 3, 3, 7, 3, 5, 3, 3, 137, 3, 3, 149, 3, 5, 3, 7, 3, 3, 3, 179, 3, 5, 3, 191, 3, 197, 3, 3, 11, 3, 5, 3, 13, 3, 227, 3, 3, 239, 3, 5, 3, 3, 3, 3, 269, 3, 5, 3

Offset

1,1

Comments

The records of the sequence form sequence of lesser numbers of twin primes.

The sequence contains all odd primes. Cf. comment by R. Israel in A242033. - Vladimir Shevelev, Aug 16 2014

Links

Table of n, a(n) for n=1..78.

Mathematica

lpf[n_]:=lpf[n]=First[First[FactorInteger[n]]]; (* least prime factor *)
A242034=Map[lpf[#-3]&, Select[Range[6, 300, 2], lpf[#-1]>lpf[#-3]&](*A243937*)] (* Peter J. C. Moses, Aug 14 2014 *)

Crossrefs

Cf. A245024, A243937, A242033, A020639.

Sequence in context: A336872 A167221 A177930 * A336863 A205708 A309392

Adjacent sequences: A242031 A242032 A242033 * A242035 A242036 A242037

Keyword

nonn

Author

Vladimir Shevelev, Aug 12 2014

Extensions

More terms from Peter J. C. Moses, Aug 12 2014

Status

approved