OFFSET
1,1
COMMENTS
Each cluster of entries is approximately a power of e from the previous cluster.
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..1161 (first 296 terms from Charles R Greathouse IV)
Konstantinos N. Gaitanas, An explicit formula for the prime counting function, arXiv preprint arXiv:1311.1398 [math.NT], 2013.
S. W. Golomb, On the Ratio of N to π(N), The American Mathematical Monthly 69.1 (1962): 36-37.
EXAMPLE
120 is a member as there are exactly 30 primes less than 120 and 30 * 4 = 120.
MAPLE
select(t -> t mod numtheory:-pi(t) = 0, [$2..10^5]); # Robert Israel, Jul 03 2016
MATHEMATICA
Select[ Range[2, 10^5], IntegerQ[ # / PrimePi[ # ]] & ]
Select[Range[1000], Divisible[#, PrimePi[#]] &] (* Requires version 6.0+. Alonso del Arte, May 24 2015 *)
PROG
(PARI) is(n)=n%primepi(n)==0 \\ Charles R Greathouse IV, Sep 14 2015
(Magma) [n: n in [2..10^5] | n mod #PrimesUpTo(n) eq 0]; // Vincenzo Librandi, Jul 04 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Nov 07 2000
EXTENSIONS
More terms from James A. Sellers, Nov 08 2000
a(297)-a(1161) obtained from the values of A038625 computed by Jan Büthe. - Giovanni Resta, Aug 31 2018
STATUS
approved