OFFSET
1,2
FORMULA
a(n) = min{x: gcd(c(x), x)=n}, where c(x) is the x-th composite number.
EXAMPLE
50th composite is 70, gcd(50,70)=10 appears first here, a(10)=50.
MATHEMATICA
f[x_] := FixedPoint[x+PrimePi[ # ]+1&, x] t=Table[0, {100}]; Do[s=GCD[f[n], n]; If[s<101&&t[[s]]==0, t[[s]]=n], {n, 1, 100000}]; t
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jul 22 2002
STATUS
approved