He is saying 998 is missing, as others have observed. He is also saying that if you took the string of digits and did a string search for "998", you'd obviously find those digits together in other places (specifically during the sequence of 979 980 981).
I had to re-read what the parent poster said to get it. So I thought I'd explain what he means when he says:
> Also, "998" doesn't appear 'in sequence' (it obviously appears as 97[9 98]0 981).
He is saying 998 is missing, as others have observed. He is also saying that if you took the string of digits and did a string search for "998", you'd obviously find those digits together in other places (specifically during the sequence of 979 980 981).
You'd also find them at 799 800 801.