a(n) = ( (6 + sqrt(6))^n - (6 - sqrt(6))^n )/(2*sqrt(6)).

A154237

a(n) = ( (6 + sqrt(6))^n - (6 - sqrt(6))^n )/(2*sqrt(6)).

Terms

    a(0) =1a(1) =12a(2) =114a(3) =1008a(4) =8676a(5) =73872a(6) =626184a(7) =5298048a(8) =44791056a(9) =378551232a(10) =3198883104a(11) =27030060288a(12) =228394230336

External references