a(n+1) = a(n) written in base 3 and read as if in base 27 (and recorded in base 10).
Number of distinct n-ary operators in a ternary logic. - Ross Drewe, Feb 13 2008
Table of n, a(n) for n=0..4.
Cf. A001146, A023365.
Sequence in context: A122217 A068221 A068222 * A014222 A071107 A162414
Adjacent sequences: A055774 A055775 A055776 * A055778 A055779 A055780
Henry Bottomley, Jul 12 2000
Next term is too big to include.