Numbers whose even divisors have an integer harmonic mean.

Terms

a(0) =2a(1) =6a(2) =12a(3) =30a(4) =56a(5) =84a(6) =168a(7) =270a(8) =280a(9) =540a(10) =616a(11) =840a(12) =992a(13) =1092a(14) =1344a(15) =2856a(16) =2976a(17) =3276a(18) =3780a(19) =4590a(20) =5320a(21) =5940a(22) =7560a(23) =12400a(24) =12420a(25) =14880a(26) =16256a(27) =16380a(28) =18848a(29) =24360