A055777 a(n) = 3^(3^n).

3, 27, 19683, 7625597484987, 443426488243037769948249630619149892803

Offset: 0

Author

Henry Bottomley, Jul 12 2000

Keywords

• nonn

Comments

Next term is too big to include.

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

The next term has 116 digits. - Harvey P. Dale, Mar 28 2019

Links

• Amiram Eldar, Table of n, a(n) for n = 0..6

Crossrefs

Cf. A001146, A023365, A383817.

Programs

Mathematica

NestList[#^3&,3,5] (* Harvey P. Dale, Mar 28 2019 *)

Python

print([3**(3**n) for n in range(5)]) # Michael S. Branicky, Mar 27 2021

Formula

a(n) = a(n-1)^3.

Sum_{n>=0} 1/a(n) = A383817. - Amiram Eldar, May 16 2025