OFFSET
1,2
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
EXAMPLE
6 is the first non-prime-power.
Since 6 = 2*3 and 3-2 = 1, then a(1) = 1.
MATHEMATICA
Min[Differences[FactorInteger[#][[All, 1]]]]&/@ Select[Range[ 2, 150], !PrimePowerQ[ #]&] (* Harvey P. Dale, Jun 22 2021 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Leroy Quet, Jan 02 2005
EXTENSIONS
More terms from Franklin T. Adams-Watters, Aug 29 2006
STATUS
approved