OFFSET
1,21
COMMENTS
a(n)=min (abs(n-k) : where k runs through the prime powers)
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
MATHEMATICA
nn = 100; pp = Select[Range[2, Prime[1 + PrimePi[nn]]], Length[FactorInteger[#]] == 1 &]; Table[Min[Abs[n - pp]], {n, nn}] (* T. D. Noe, Mar 14 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Mar 08 2003
STATUS
approved
