Apply the morphism 1 -> 12, 2 -> 13, 3 -> 14, 4 -> 1 n times to 1, and concatenate the resulting string.

A317955

Apply the morphism 1 -> 12, 2 -> 13, 3 -> 14, 4 -> 1 n times to 1, and concatenate the resulting string.

Terms

    a(0) =1a(1) =12a(2) =1213a(3) =12131214

External references