a(n) = 10*6^n+1.

Terms

a(0) =11a(1) =61a(2) =361a(3) =2161a(4) =12961a(5) =77761a(6) =466561a(7) =2799361a(8) =16796161a(9) =100776961a(10) =604661761a(11) =3627970561a(12) =21767823361a(13) =130606940161a(14) =783641640961