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

1,2

Links

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

Example

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

Mathematica

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

Prog

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

Crossrefs

Cf. A057809.

Sequence in context: A037429 A230452 A270478 * A257482 A023167 A177380

Adjacent sequences: A235492 A235493 A235494 * A235496 A235497 A235498

Keyword

nonn

Author

Vincenzo Librandi, Jan 11 2014

Status

approved