a(n) = 48*2^n + 26 (n>=1).

Terms

a(0) =122a(1) =218a(2) =410a(3) =794a(4) =1562a(5) =3098a(6) =6170a(7) =12314a(8) =24602a(9) =49178a(10) =98330a(11) =196634a(12) =393242a(13) =786458a(14) =1572890a(15) =3145754a(16) =6291482a(17) =12582938a(18) =25165850a(19) =50331674a(20) =100663322a(21) =201326618a(22) =402653210a(23) =805306394a(24) =1610612762a(25) =3221225498a(26) =6442450970a(27) =12884901914a(28) =25769803802a(29) =51539607578