a(n) = a(n-1) * (11*a(n-1) - a(n-2)) / (a(n-1) + 4*a(n-2)), a(0) = a(1) = 0, a(2) = 1.

A173731

a(n) = a(n-1) * (11*a(n-1) - a(n-2)) / (a(n-1) + 4*a(n-2)), a(0) = a(1) = 0, a(2) = 1.

Terms

    a(0) =0a(1) =0a(2) =1a(3) =11a(4) =88a(5) =638a(6) =4466a(7) =30856a(8) =212135a(9) =1455685a(10) =9981840a(11) =68428140a(12) =469043796a(13) =3214953456a(14) =22035826813a(15) =151036348463

External references