A218478 - cp's OEIS frontend

A218478 Number of 3n-length 8-ary words, either empty or beginning with the first letter of the alphabet, that can be built by repeatedly inserting triples of identical letters into the initially empty word.

n	a(n)
0	1
1	1
2	22
3	631
4	20546
5	721071
6	26594464
7	1016157668
8	39868799482
9	1596785816431
10	65014851904262
11	2683064838415039
12	111976833827421368
13	4717961282984709124
14	200410768873037098384
15	8573481927644738115096
16	369045717586929668129706
17	15972561730958196240953007

[1, 1, 22, 631, 20546, 721071, 26594464, 1016157668, 39868799482, 1596785816431, 65014851904262, 2683064838415039, 111976833827421368, 4717961282984709124, 200410768873037098384, 8573481927644738115096, 369045717586929668129706, 15972561730958196240953007]

cp's OEIS Frontend

A218478 Number of 3n-length 8-ary words, either empty or beginning with the first letter of the alphabet, that can be built by repeatedly inserting triples of identical letters into the initially empty word.

Table of values

List of values