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location Vienna, Austria
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visits member for 1 year, 11 months
seen Apr 13 at 9:03
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Feb
16
comment Showing $\gcd(n^3 + 1, n^2 + 2) = 1$, $3$, or $9$
i think after you have shown that 9=0 (mod p) you are done. you have assumed nothing special about p except that it is a common divisor of n^3+1 and n^2+2. So if you choose p:=gcd(n^3+1,n^2+2) if foolows that gcd is 1,3 or 9
Feb
16
comment Showing $\gcd(n^3 + 1, n^2 + 2) = 1$, $3$, or $9$
i think it is not necessary to schow for each of the numbers 1,3,9 that there is an appropriate n. this is not part of the question. if an arbitrary common divisor of n^3+1 and n^2+2 divides 9 than you have shown that gcd(n^3+1,n^2+2) is 1,3 or 9
Feb
16
comment Showing $\gcd(n^3 + 1, n^2 + 2) = 1$, $3$, or $9$
gcd(c*a,b)|c*g(a,b), so the only spurious factor that could be added to gcd(n^2+2,2*n-1) by calculating (2*(n^2+1),2*n-1) instead of, is therefore 2. But 2 will not be added because 2*n-1 is odd.
Feb
12
awarded  Critic
Feb
7
comment RSA calculations
what is B? q^3+3*q^2*(1-q)=0.104, if q=0.2 so q_B<q. How do you deduce the probability?
Feb
7
comment Proving a subset is closed under a binary operation on a set
as you stated you should prove that a*b in H if a and b in H. a*b in H means that (a*b)*(a*b)=(a*b). can you prove this?
Feb
5
awarded  Scholar
Feb
5
accepted find all positive integers satisfying $2x^2 - y^{14} = 1$
Feb
4
awarded  Student
Feb
4
asked find all positive integers satisfying $2x^2 - y^{14} = 1$
Feb
4
revised Can you combine axioms for a vector space?
more clear formulation
Feb
4
revised Can you combine axioms for a vector space?
more precise, typos
Feb
4
answered Can you combine axioms for a vector space?
Feb
1
revised 100 Soldiers riddle
added 1 characters in body
Feb
1
comment 100 Soldiers riddle
This is the answer from the original paper @Peter-Shor points to, but "...That means 100 soldiers lost 3 limbs..." is not evident to me. I would prefer the following formulation. A soldier has at most 4 missing limbs. if ther are not more than 9 soldiers that have 4 missing limbs than there are at most 9*4+91*3=309 missing limbs. Therefore there must be at least 10 soldiers that have 4 missing limbs.
Feb
1
revised 100 Soldiers riddle
added 235 characters in body
Feb
1
answered 100 Soldiers riddle
Jan
3
comment An example of an easy to understand undecidable problem
there is a typo (a,bba) instead of (a,baa) for tuple 1. but it is not allowed to change only one character
Jun
29
awarded  Enthusiast
Jun
26
comment Prove that $6|2n^3+3n^2+n$
if you want to use induction then use the fact that for your polynomial $p(n)=n(n+1)(2n+1)$ the following property holds: $$p(n+1)=6(n+1)^2+p(n)$$