%I #6 Jul 03 2016 00:17:36
%S 2,7,5,3,89,3,83,3,7,71,3,3,59,3,53,47,41,3,3,29,3,3,17,11,3,29,3,19,
%T 3,587,3,11,863,3,23,3,3,3,7,827,821,3,809,3,11,3,3,3,773,3,13,761,3,
%U 7,743,11,17,3,3,719,3,7,3,13,3,683,3,3,653,3,647,641,3,3,3,617,13,3,599
%N Smallest prime divisor of A160668(n).
%e a(1)=2 because in A160668 a(1)=8, so the first prime divisor is 2.
%o (UBASIC) 10 'recipseq, _Enoch Haga_, May 22 2009 20 N=3:print N:C=2 30 A=3:S=sqrt(N) 40 B=N/A 50 if A*B=int(N) then 70 60 A=A+2:if A<S then 40 70 if N=prmdiv(N) then print N;:else 130 80 if alen(N)=1 then print 10^1-N;:P=prmdiv(10^1-N):goto 120 90 if alen(N)=2 then print 10^2-N;:P=prmdiv(10^2-N):goto 120 100 if alen(N)=3 then print 10^3-N;:P=prmdiv(10^3-N):goto 120 110 if alen(N)=4 then print 10^4-N;:P=prmdiv(10^4-N) 120 print P;C:C=C+1:stop 130 N=N+2:S=sqrt(N):goto 40
%Y Cf. A160668 A160670
%K easy,nonn
%O 1,1
%A _Enoch Haga_, May 23 2009