OFFSET
1,1
COMMENTS
3-almost prime analog of A076265. (Semiprime analog of A076265 is A118056.) Fractions are 1/16777216, 265721/4458050224128, 75047458863267833/1259085058409489202413568, 938093235790847912650094635296999121 / 15738563230118615030169600000000000000000000, 2771420766426289313598405374054613260285749630619149892803 / 46496637333593157266125580467610571799579852800000000000000000000.
FORMULA
EXAMPLE
MATHEMATICA
Accumulate[1/#^#&/@Select[Range[30], PrimeOmega[#]==3&]]//Denominator (* Harvey P. Dale, Apr 05 2020 *)
CROSSREFS
KEYWORD
easy,frac,nonn
AUTHOR
Jonathan Vos Post, Apr 11 2006
STATUS
approved