OFFSET
1,3
LINKS
Jason Kimberley, Table of n, a(n) for n = 1..10000
MATHEMATICA
Array[(PrimePi@ # - Boole[# > 1]) (PrimePi[2 #] - Boole[2 # > 1]) &, 60] (* Michael De Vlieger, May 27 2018 *)
PROG
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jason Kimberley, May 15 2018
STATUS
approved