Number of amicable pairs with lesser member at most 2^n.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =1a(8) =1a(9) =1a(10) =2a(11) =3a(12) =5a(13) =7a(14) =8a(15) =9a(16) =16a(17) =22a(18) =30a(19) =42a(20) =57a(21) =68a(22) =95a(23) =133a(24) =167a(25) =205a(26) =257a(27) =342a(28) =460a(29) =605