a(n) = (n-1)*2^n + 1.

Terms

a(0) =0a(1) =1a(2) =5a(3) =17a(4) =49a(5) =129a(6) =321a(7) =769a(8) =1793a(9) =4097a(10) =9217a(11) =20481a(12) =45057a(13) =98305a(14) =212993a(15) =458753a(16) =983041a(17) =2097153a(18) =4456449a(19) =9437185a(20) =19922945a(21) =41943041a(22) =88080385a(23) =184549377a(24) =385875969a(25) =805306369a(26) =1677721601a(27) =3489660929a(28) =7247757313a(29) =15032385537