Number of integers m <= 2^n such that d(m) = 2^k for some k = 0, 1, 2, 3, ...

Terms

a(0) =2a(1) =3a(2) =7a(3) =12a(4) =23a(5) =45a(6) =89a(7) =178a(8) =356a(9) =707a(10) =1409a(11) =2822a(12) =5639a(13) =11273a(14) =22546a(15) =45088a(16) =90165a(17) =180315a(18) =360637a(19) =721258a(20) =1442491a(21) =2884973a(22) =5769941a(23) =11539858a(24) =23079721a(25) =46159395a(26) =92318705a(27) =184637321a(28) =369274467a(29) =738548867