a(n) = 33*2^(n+1) + 7.

Terms

a(0) =73a(1) =139a(2) =271a(3) =535a(4) =1063a(5) =2119a(6) =4231a(7) =8455a(8) =16903a(9) =33799a(10) =67591a(11) =135175a(12) =270343a(13) =540679a(14) =1081351a(15) =2162695a(16) =4325383a(17) =8650759a(18) =17301511a(19) =34603015a(20) =69206023a(21) =138412039a(22) =276824071a(23) =553648135a(24) =1107296263a(25) =2214592519a(26) =4429185031a(27) =8858370055a(28) =17716740103a(29) =35433480199