a(0)=1, a(n+1) = (a(n)*6) XOR a(n).

Terms

a(0) =1a(1) =7a(2) =45a(3) =291a(4) =2033a(5) =10327a(6) =55901a(7) =377971a(8) =2580161a(9) =13329991a(10) =68092909a(11) =475337827a(12) =3047910961a(13) =21335374615a(14) =108342024605a(15) =611555770419