Even multiply-perfect numbers divided by 2.

Terms

a(0) =3a(1) =14a(2) =60a(3) =248a(4) =336a(5) =4064a(6) =15120a(7) =16380a(8) =261888a(9) =1089270a(10) =11784960a(11) =16775168a(12) =22766400a(13) =71495424a(14) =229909120a(15) =689727360a(16) =738152448a(17) =4294934528a(18) =7091219520a(19) =15999197760a(20) =21930739200a(21) =25500590080a(22) =33216860160