A152769 Numbers n such that pi(n) is nonprime.
1, 2, 7, 8, 9, 10, 13, 14, 15, 16, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 37, 38, 39, 40, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 61, 62, 63, 64, 65, 66, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99
Offset: 1
Links
- Omar E. Pol, Divisors and pi(x)
Programs
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Mathematica
Select[Range[100],!PrimeQ[PrimePi[#]]&] (* Harvey P. Dale, May 06 2019 *)
Extensions
Edited by N. J. A. Sloane, Dec 19 2008
Comments