no single taker?
1) Prove that there exist arbitrarily long arithmetic progressions with all the terms being powers of integers.
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5 Answers
ofc dude its obvious
eg 1 1 1 1 1 1
4 4 4 4 4 4 4 4 4 4 ..........
even i was going to give the same solution :D
but then i thought that it wud be unfair to the question ;)
I am sure the question has the phrase "unequal terms"
I have seen the question but dont know the prooff.. the proof i saw had arguments on Real analysis!
i guess proof gots to deal with the fact we got infinite no of powers of integers
By rk denote member of the finite arithmetic progression
n!+1+k(n-1)!,k=1..n.
It is obvious gcd(ri,rj)=1.
Let ai=si*r1*r2*...*rn/ri,
si is positive integer and satisfies the condition
ri|(ai+1) (gcd(r1*r2*...*rn/ri ,ri)=1
==>si exists.
Denote m=r1a1*...*rnan.
The sequence r1*m, r2*m,..., rn*m is required since rk*m=b^rk for some positive integer b.