If the styles are fairly close most do not even bother to wash the yeast and just pitch directly on the "old" yeast slurry. I would not worry much about a starter since you will probably have enough cells from the get go. That is unless you wash it and have a very thin slurry. I usually wash and store my yeast as well as bank some of it in a freezer and have been reusing some of it thats around 1 year old (washed) longer for banked frozen.
"Look, let me explain something to you. I'm not Mr. Lebowski. You're Mr. Lebowski. I'm the Dude. So that's what you call me. That or His Dudeness... Duder... or El Duderino, if, you know, you're not into the whole brevity thing." -The Dude