YOU SAID:

it begins with a followed by aa then aaa then aaaa

INTO JAPANESE

それはaaの後に続いて、次にa

BACK INTO ENGLISH

It follows aa, then a

INTO JAPANESE

それはaaに続き、次に

BACK INTO ENGLISH

It followed aa, and then

INTO JAPANESE

それはaaに続き、その後

BACK INTO ENGLISH

It followed aa, and then