No First-Hand-Neighbors!!

[BMAD]

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.

[Nins_Leprechaun]

3,1,4,2

[bonanova]

1, or 1 3.

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

[witzar]

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

[BMAD]

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

Edited July 7, 2013 by BMAD

[witzar]

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.

[BMAD]

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.

[bonanova]

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?

[BMAD]

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

[bonanova]

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

[BMAD]

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.