[seqfan] Re: a result which I don't understand

[Hans Havermann]

> FindInstance[a[1]!=a[2]!=a[3],{a[1],a[2],a[3]},Integers]. Mathematica responds with 2,1,4.

What's not to understand? It found an instance. According to the documentation, "the instances returned by FindInstance typically correspond to special or interesting points in the set." Bottom line, it's up to Mathematica (not you) to decide what the output is. Don't like it? Don't use it.