Integer part of (2^(n - 1) - 1)*sqrt(3) + 1.

Terms

a(0) =0a(1) =1a(2) =2a(3) =6a(4) =13a(5) =26a(6) =54a(7) =110a(8) =220a(9) =442a(10) =886a(11) =1772a(12) =3546a(13) =7093a(14) =14188a(15) =28377a(16) =56755a(17) =113510a(18) =227022a(19) =454045a(20) =908092a(21) =1816186a(22) =3632373a(23) =7264746a(24) =14529494a(25) =29058989a(26) =58117980a(27) =116235961a(28) =232471923a(29) =464943847