Practical numbers of the form 2*f where f is a product of multiples of Fermat primes (A143512).

Terms

a(0) =2a(1) =6a(2) =18a(3) =30a(4) =54a(5) =90a(6) =150a(7) =162a(8) =270a(9) =306a(10) =450a(11) =486a(12) =510a(13) =750a(14) =810a(15) =918a(16) =1350a(17) =1458a(18) =1530a(19) =2250a(20) =2430a(21) =2550a(22) =2754a(23) =3750a(24) =4050a(25) =4374a(26) =4590a(27) =5202a(28) =6750a(29) =7290