Numbers whose divisors have a harmonic mean with a denominator 2.

Terms

a(0) =3a(1) =15a(2) =42a(3) =84a(4) =135a(5) =308a(6) =420a(7) =546a(8) =1428a(9) =1488a(10) =1890a(11) =2295a(12) =2660a(13) =3780a(14) =6210a(15) =7440a(16) =9424a(17) =12180a(18) =13392a(19) =18018a(20) =20832a(21) =24384a(22) =24570a(23) =43152a(24) =43400a(25) =64260a(26) =66960a(27) =77490a(28) =90090a(29) =98420