A235495 Numbers n such that pi(2n) divides n.

1, 2, 3, 4, 48, 50, 60, 504, 540, 546, 558, 561, 564, 567, 4204, 4212, 4220, 4228, 4232, 4236, 32270, 32290, 32305, 32310, 32325, 32345, 32350, 32355, 32360, 240426, 240432, 240504, 240510, 240516, 240522, 240528, 240534, 240540, 240546, 240648, 240678, 240684

Offset: 1

Author

Vincenzo Librandi, Jan 11 2014

Keywords

• nonn

Examples

			48 is in the sequence because pi(2*48) = 24 and 24 divides 48.
		

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..59

Crossrefs

Cf. A057809.

Programs

Mathematica

Select[Range[10^6],IntegerQ[#/PrimePi[2#]]&]

PARI

is(n)=n%primepi(2*n)==0 \\ Charles R Greathouse IV, Jan 12 2014