a(n) = n*4^n + 1.

Terms

a(0) =1a(1) =5a(2) =33a(3) =193a(4) =1025a(5) =5121a(6) =24577a(7) =114689a(8) =524289a(9) =2359297a(10) =10485761a(11) =46137345a(12) =201326593a(13) =872415233a(14) =3758096385a(15) =16106127361a(16) =68719476737a(17) =292057776129