A160669 Smallest prime divisor of A160668(n).

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, 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, 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

Offset

1,1

Links

Table of n, a(n) for n=1..79.

Example

a(1)=2 because in A160668 a(1)=8, so the first prime divisor is 2.

Prog

(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

Crossrefs

Cf. A160668 A160670

Sequence in context: A171037 A246205 A340117 * A301816 A021367 A217102

Adjacent sequences: A160666 A160667 A160668 * A160670 A160671 A160672

Keyword

easy,nonn

Author

Enoch Haga, May 23 2009

Status

approved