Sorry for delay, guys, I've been offline for a while...

FF, I for one am going to admit I had never heard of any of your 'illions' before this. Hence their non-inclusion in my process. I went away and looked them up in my Shorter Oxford (1969, inherited from grandparents)

Octillion
eighth power of a million, denoted by 1 followed by 48 ciphers. (in US, following later French usage, the ninth power of a thousand, denoted by one and 27 ciphers)

quintillion
a) in Britain, the fifth power of a million (1 followed by thirty ciphers)
b) in US (as in France) the cube of a million (1 followed by 18 ciphers)

septillion
the seventh power of a million, denoted by one followed by 32 ciphers. In American (following the later French use) the eighth power of a thousand, denoted by 1 followed by 24 ciphers.

This leads me to the following thoughts:
- just what is the logic behind the US/French way of assigning values to these words???
- in modern 'international' English, do these words have one standard accepted definition? Are they in fact used?
- (insert desperately-justifying-own-lack-of-knowledge-and-hence-not-using-them-in-proof emoticon here ) given obscurity/dual definitions, do they really qualify as 'officially recognised'?
- how bizarrely different the wording is of entries in the same dictionary for such closely related words!