a(n) = 2^n - 243.

Terms

a(0) =-242a(1) =-241a(2) =-239a(3) =-235a(4) =-227a(5) =-211a(6) =-179a(7) =-115a(8) =13a(9) =269a(10) =781a(11) =1805a(12) =3853a(13) =7949a(14) =16141a(15) =32525a(16) =65293a(17) =130829a(18) =261901a(19) =524045a(20) =1048333a(21) =2096909a(22) =4194061a(23) =8388365a(24) =16776973a(25) =33554189a(26) =67108621a(27) =134217485a(28) =268435213a(29) =536870669