a(n) = 2*a(n-1) + 10*a(n-2), with a(0) = 1, a(1) = 12.

Terms

a(0) =1a(1) =12a(2) =34a(3) =188a(4) =716a(5) =3312a(6) =13784a(7) =60688a(8) =259216a(9) =1125312a(10) =4842784a(11) =20938688a(12) =90305216a(13) =389997312a(14) =1683046784a(15) =7266066688a(16) =31362601216a(17) =135385869312a(18) =584397750784