OFFSET
1,6
LINKS
N. J. A. Sloane, Table of n, a(n) for n = 1..10000
FORMULA
a(n) = A294602(prime(n)). - R. J. Mathar, Dec 17 2017
a(n) = n-1-pi(prime(n)/2). - N. J. A. Sloane, Nov 04 2020
MAPLE
A107347 := n -> n-1-pi(ithprime(n)/2);
[seq(A107347(n), n=1..100)]; # N. J. A. Sloane, Nov 04 2020
MATHEMATICA
fQ[n_] := Plus @@ Last /@ FactorInteger[n] == 2; f[n_] := Count[fQ /@ Range[Prime[n] + 1, Prime[n + 1] - 1], True]; Table[ f[n], {n, 78}] (* Robert G. Wilson v, May 28 2005 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Giovanni Teofilatto, May 23 2005
EXTENSIONS
Corrected and extended by Robert G. Wilson v, May 28 2005
STATUS
approved