OFFSET
1,3
COMMENTS
Complement of A045917(n).
LINKS
FORMULA
a(n) = n - A045917(n).
MAPLE
MATHEMATICA
Table[n - Sum[(PrimePi[2 n - i] - PrimePi[2 n - i - 1]) (PrimePi[i] - PrimePi[i - 1]), {i, n}], {n, 100}] (* Wesley Ivan Hurt, Apr 07 2018 *)
f[n_]:=Length[Select[2 n - Prime[Range[PrimePi[n]]], PrimeQ]]; Table[n - f[n], {n, 100}] (* Vincenzo Librandi, Apr 10 2018 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Wesley Ivan Hurt, Jun 30 2013
STATUS
approved