Base 4 digits are, in order, the first n terms of the sequence (1, 3, 21, 203, 2021, 20203, 202021, 2020203, 20202021, 202020203, ... ).
1, 3, 9, 35, 137, 547, 2185, 8739, 34953, 139811, 559241, 2236963, 8947849
1 seqfan posts
Thu Nov 19 17:19:12 CET 2009 [seqfan] detective work related to Creighton Dement's "Floretions"