Naming double bond sidechain
It looks like you're correct.

This molecule has been given 2-ethyl-1-hexene or 2-ethylhex-1-ene
  

Another name for your molecule would be 3-methylidenedecane. 

Added from Wikipedia:      

The trivial name carbene is the preferred IUPAC name. 

The systematic names methylidene and dihydridocarbon are constructed according to the substitutive and additive nomenclatures, respectively.