Odd BGP AS Path

Hi all, Probably a silly question, but can anyone explain to me this: 3561 3356 9031 {35821,35821,35821,35821} i To explain it a bit better, I'm looking at real routing information from routeviews (#3). According to RFC 4271 (9.2.2.2 Aggregating Routing Information):

For the purpose of aggregating AS_PATH attributes, we model each AS within the AS_PATH attribute as a tuple <type, value>, where "type" identifies a type of the path segment the AS belongs to (e.g., AS_SEQUENCE, AS_SET), and "value" identifies the AS number. ... No tuple of type AS_SET with the same value SHALL appear more than once in the aggregated AS_PATH.

Am I misreading things, or is this path information out of spec? Cheers Heath