a(n) is the numerator of the median abundancy index of the first 2^n + 1 positive integers.

Terms

a(0) =4a(1) =4a(2) =13a(3) =3a(4) =32a(5) =45a(6) =63a(7) =90a(8) =111a(9) =162a(10) =210a(11) =237a(12) =7502a(13) =11776a(14) =240a(15) =2944a(16) =3008a(17) =11648a(18) =225152a(19) =478080a(20) =2704000a(21) =1548160a(22) =2462400a(23) =10128256a(24) =4999296a(25) =8640768a(26) =48264064a(27) =32347648