Dodgy story supported by account provided by one mathematician (9)
I believe the answer is:
fibonacci
'mathematician' is the definition.
(I've seen this before)
'dodgy story supported by account provided by one' is the wordplay.
'dodgy story' becomes 'fib' (synonyms. I am not sure about the 'dodgy' bit.).
'supported by' becomes 'on' (something on something else is supported by it).
'account' becomes 'acc'.
'provided by' is a charade indicator (letters next to each other).
'one' becomes 'i' (Roman numeral).
'fib'+'on'+'acc'+'i'='FIBONACCI'
Can you help me to learn more?
(Other definitions for fibonacci that I've seen before include "Italian mathematician who gave name to sequence" , "Maths whiz" , "Mathematician giving name to a series" , "Thirteenth century Italian mathematician associated with series one, one, two, three, five, eight etc" .)