a(n) = 352*2^n + 34.

Terms

a(0) =386a(1) =738a(2) =1442a(3) =2850a(4) =5666a(5) =11298a(6) =22562a(7) =45090a(8) =90146a(9) =180258a(10) =360482a(11) =720930a(12) =1441826a(13) =2883618a(14) =5767202a(15) =11534370a(16) =23068706a(17) =46137378a(18) =92274722a(19) =184549410a(20) =369098786a(21) =738197538a(22) =1476395042a(23) =2952790050a(24) =5905580066a(25) =11811160098a(26) =23622320162a(27) =47244640290