[Haskell-begin] Alternating sequence

[Dirk Markert]

I am trying to generate the following list:
2, 3, 5 -- and then alternating (+2) resp (+4) -- 7, 11, 13, 17, 19, 23

I came up with the following solution
2:3:unfoldr (\(a,b) -> Just (a,(a+b, if b == 2 then 4 else 2))) (5,2)

Are there easier ways to generate the desired list?

Dirk
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