A247872 Least prime factor of A247681(n).

5, 7, 5, 7, 5, 11, 17, 5, 7, 19, 5, 11, 7, 5, 13, 5, 11, 23, 5, 19, 7, 5, 13, 7, 5, 17, 5, 7, 13, 5, 23, 7, 5, 29, 17, 5, 11, 13, 5, 31, 7, 37, 19, 5, 11, 7, 5, 17, 5, 7, 11, 5, 29, 7, 5, 17, 11, 5, 31, 23, 41, 5, 13, 7, 5, 19, 7, 5, 13, 5, 7, 5, 23, 7, 5, 19, 11, 31, 5, 5, 7, 11, 5, 37, 7, 5, 47, 53, 11, 5, 7, 43, 13, 5, 7

Offset

2,1

Links

Odimar Fabeny, Table of n, a(n) for n = 2..10000

Maple

count:= 0:
for n from 1 while count < 100 do
   m:= 1+18*n;
   if not isprime(m) then
      count:= count+1;
      A[count]:= min(numtheory:-factorset(m))
   fi
od:
seq(A[i], i=1..count); # Robert Israel, Sep 30 2014

Crossrefs

Cf. A056608, A247681.

Sequence in context: A372204 A215732 A010718 * A306400 A090987 A278813

Adjacent sequences: A247869 A247870 A247871 * A247873 A247874 A247875

Keyword

nonn,easy

Author

Odimar Fabeny, Sep 25 2014

Status

approved