a(n) = 2^(n + 11) - 11.

Terms

a(0) =2037a(1) =4085a(2) =8181a(3) =16373a(4) =32757a(5) =65525a(6) =131061a(7) =262133a(8) =524277a(9) =1048565a(10) =2097141a(11) =4194293a(12) =8388597a(13) =16777205a(14) =33554421a(15) =67108853a(16) =134217717a(17) =268435445a(18) =536870901a(19) =1073741813a(20) =2147483637a(21) =4294967285a(22) =8589934581a(23) =17179869173