

A104904


Numbers n such that d(n)*pi(n)=n, where d(n) is the number of positive divisors of n.


2




OFFSET

1,1


COMMENTS

Next term is greater than 3*10^9.


LINKS



EXAMPLE

189961452 is in the sequence because d(189961452)=18; pi(189961452)=10553414 & 18*10553414=189961452.


MATHEMATICA

Do[If[DivisorSigma[0, n]*PrimePi[n] == n, Print[n]], {n, 2000000000}]


CROSSREFS



KEYWORD

hard,more,nonn


AUTHOR



EXTENSIONS



STATUS

approved



