Squarefree part of 2^n+1 : the smallest number such that a(n)*(2^n+1) is a square.

Terms

a(0) =2a(1) =3a(2) =5a(3) =1a(4) =17a(5) =33a(6) =65a(7) =129a(8) =257a(9) =57a(10) =41a(11) =2049a(12) =4097a(13) =8193a(14) =16385a(15) =3641a(16) =65537a(17) =131073a(18) =262145a(19) =524289a(20) =1048577a(21) =233017a(22) =4194305a(23) =8388609a(24) =16777217a(25) =33554433a(26) =67108865a(27) =1657009a(28) =268435457a(29) =536870913