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# No First-Hand-Neighbors!!

## Question

Create the shortest possible sequence (using numbers from 1,2,...n) such that no number is next to its first-hand neighbors (e.g. the number 2 cannot be next to numbers 1 and 3, which are its first-hand neighbors).

e.g.

1,6,3,5,2,4,7 Here is a sequence using 7 numbers that meets the requirement.

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3,1,4,2

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1, or 1 3.

I get what you're asking, and neither fits.

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Clearly empty sequence (length 0) wins the contest..

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the sequence must start at 1 and go to some n (consecutively) where n does not equal 1.

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the sequence must start at 1 and go to some n (consecutively) where n does not equal 1.

Now it's a different story. BTW "best answer" sequence starts with 3 not with 1.

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I am sorry, I am working on translating to English better. I mean to say that the numbers you use must contain the sequence from 1 to some N but don't have to start that way. So 1, 3, 5, 2, and 4 are fine since it contains numbers 1-5 and no first hand neighbors.

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It was clear to me what you were asking.

I just included, for fun, something outside the "box".

Your English is fantastically good, even for a first-language writer,

No need to apologize.

Did I hear somewhere that Russian is your first language?

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My first language is Ukrainian but I do speak Russian sufficiently.

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My first language is English and I'm still learning it. My writing is OK but my speech needs work.

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all of us here are still learning, i believe. which is why I believe we come to a site dedicated to challenge how we think.

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