The phrase "at least one example" is correct and usable in written English.
You can use it when you want to indicate that a minimum of one instance or illustration is required or expected.
Example: "In your report, please provide at least one example to support your argument."
Alternatives: "a minimum of one example" or "one or more examples".
At least one example of short (5 bp), telomere-like repeats on a linear plasmid has been reported for the fungus Fusarium oxysporum (Walther and Kennell 1999) (the F. oxysporum genome does not contain telomeres since it is circular [ Marriott et al. 1984]).
A further complication is that MoRFs can exhibit partner-dependent structures, with at least one example morphing into helix, sheet, or irregular structure, depending on the partner [ 28].
I bet you can probably give at least one example of a health issue you experienced that was brought on by stress.
Provide at least one example of this process.
But what Amazon did with Diapers.com provides at least one example.
We already know of at least one example where this approach can work.
There is at least one example, he said, of an American court ordering a Web site not to link to content it had been ordered to take down.
For those of you keeping score at home, that last sentence contained a verbal noun, a split infinitive, an improper -ize, an inflectional comparative, a blatantly misleading word choice, at least one example of catachresis, an unnecessarily passive construction — and it ended with a preposition.
We explicitly describe three different approaches for fabrication of tubular nanostructures, each approach is highlighted by at least one example.
What is more worrisome here is that there exists at least one example [20] of a linearisable system which possesses an explicit invariant and still has unconfined singularities.
We discarded all targets that did not meet the minimum requirement of having at least one example of both classes in each fold.
