A218475 - cp's OEIS frontend

A218475 Number of 3n-length 5-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	13
3	217
4	4085
5	82593
6	1751197
7	38413481
8	864413317
9	19842830065
10	462825376685
11	10937407206265
12	261311076852245
13	6301225556698177
14	153160687795008445
15	3748598210810053449
16	92303640047399410341
17	2285025852515378528913
18	56836898766186234593485

[1, 1, 13, 217, 4085, 82593, 1751197, 38413481, 864413317, 19842830065, 462825376685, 10937407206265, 261311076852245, 6301225556698177, 153160687795008445, 3748598210810053449, 92303640047399410341, 2285025852515378528913, 56836898766186234593485]

cp's OEIS Frontend

A218475 Number of 3n-length 5-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