Each term is the previous term times the number of letters in the previous number, as conventionally spelled out in English.
A129731
Each term is the previous term times the number of letters in the previous number, as conventionally spelled out in English.
Terms
- a(0) =1a(1) =3a(2) =15a(3) =105a(4) =1470a(5) =42630a(6) =1364160a(7) =75028800a(8) =3676411200a(9) =272054428800
External references
- oeis: A129731