A038190 Pagoda sequence: a(0) = b(n)-b(n-2) mod 3, where b(n) = A038189(n).

2, 2, 0, 1, 0, 2, 1, 1, 2, 2, 0, 1, 1, 2, 0, 1, 2, 2, 0, 1, 0, 2, 1, 1, 0, 2, 2, 1, 1, 2, 0, 1, 2, 2, 0, 1, 0, 2, 1, 1, 2, 2, 0, 1, 1, 2, 0, 1, 0, 2, 2, 1, 0, 2, 1, 1, 0, 2, 2, 1, 1, 2, 0, 1, 2, 2, 0, 1, 0, 2, 1, 1, 2, 2, 0, 1, 1, 2, 0, 1, 2, 2, 0, 1, 0, 2, 1, 1, 0, 2, 2, 1, 1, 2, 0, 1, 0, 2, 2, 1, 0, 2, 1, 1, 2, 2, 0, 1

Offset

-2,1

Links

Table of n, a(n) for n=-2..105.

Fred Lunnon, Pagodas and Sackcloth: Ternary Sequences of Considerable Linear Complexity, Maynooth, July 1997. Also at CiteSeerX.

Index entries for sequences that are fixed points of mappings

Formula

Repeated iteration of the inflation morphism A -> AB, B -> AD, C -> CB, D -> CD; giving ABADABCDABADCBCDABADABCDCBADCBCD ..., followed by the final morphism A -> 2201, B -> 0211, C -> 0221, D -> 1201 ., giving the Pagoda K_n mod 3 = 22010211 22011201 22010211 02211201 ...

Mathematica

Nest[ Flatten[ # /. {a -> {a, b}, b -> {a, d}, c -> {c, b}, d -> {c, d}}] &, {a}, 5] /. {a -> {2, 2, 0, 1}, b -> {0, 2, 1, 1}, c -> {0, 2, 2, 1}, d -> {1, 2, 0, 1}} // Flatten (* Robert G. Wilson v, Mar 04 2005 *)

Crossrefs

Cf. A038189.

Sequence in context: A287443 A039651 A264403 * A279947 A263571 A364060

Adjacent sequences: A038187 A038188 A038189 * A038191 A038192 A038193

Keyword

nonn

Author

Fred Lunnon

Extensions

More terms from David W. Wilson

Status

approved