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Least prime factor of A247681(n).
1

%I #16 Oct 15 2014 15:56:16

%S 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,

%T 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,

%U 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

%N Least prime factor of A247681(n).

%H Odimar Fabeny, <a href="/A247872/b247872.txt">Table of n, a(n) for n = 2..10000</a>

%p count:= 0:

%p for n from 1 while count < 100 do

%p m:= 1+18*n;

%p if not isprime(m) then

%p count:= count+1;

%p A[count]:= min(numtheory:-factorset(m))

%p fi

%p od:

%p seq(A[i],i=1..count); # _Robert Israel_, Sep 30 2014

%Y Cf. A056608, A247681.

%K nonn,easy

%O 2,1

%A _Odimar Fabeny_, Sep 25 2014