The Collaborative International Dictionary of English v.0.48:

Louisianan \Louisianan\, Louisianian \Louisianian\prop. n.
   a resident of Louisiana.
   [WordNet 1.5]

WordNet (r) 3.0 (2006):

Louisianan
    n 1: a native or resident of Louisiana [syn: Louisianan,
         Louisianian]