OFFSET
1,2
EXAMPLE
The first few fractions are 1, 5/4, 17/12, 37/24, 119/72, 631/360, 661/360, 4807/2520, 995/504, 2053/
1008, 703/336, 3599/1680, ... - N. J. A. Sloane, Dec 15 2017
MATHEMATICA
With[{nn = 45}, Numerator@ Accumulate[1/Complement[Range@ nn, Prime@ Range@ PrimePi@ nn]]] (* Michael De Vlieger, Feb 18 2017 *)
PROG
(PARI) a018252(n) = if(n==1, 1, my(i=1); forcomposite(c=1, , i++; if(i==n, return(c))))
a(n) = numerator(sum(k=1, n, 1/a018252(k))) \\ Felix Fröhlich, Feb 17 2017
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Ralf Steiner, Feb 17 2017
EXTENSIONS
More terms from Felix Fröhlich, Feb 17 2017
STATUS
approved