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seen Dec 7 '13 at 23:44

Jul
2
awarded  Curious
Nov
6
revised Concrete Mathematics - Stability of definitions in the repertoire method
edited body
Nov
4
accepted Concrete Mathematics - Stability of definitions in the repertoire method
Nov
4
comment Concrete Mathematics - Stability of definitions in the repertoire method
Brilliant! Never occurred to me to plug the closed form back into the recurrence to convince myself, but that makes sense to try since that's where the structure is coming from. Thanks :-)
Nov
4
comment Repertoire Method Clarification Required ( Concrete Mathematics )
@HansLundmark: I can see that it will be a combination of those, but I don't understand how we know A, B, and C will always be the same, which I have opened as a new question.
Nov
4
asked Concrete Mathematics - Stability of definitions in the repertoire method
Jan
27
comment How to prove $\gcd(a,\gcd(b, c)) = \gcd(\gcd(a, b), c)$?
Actually #4 is OK, it does follow from the definition if you're using the Bezout's identity version.
Jan
27
comment Blending values on the number line
Were the number lines drawn by hand or is there a plotting tool for these?
Jan
26
comment How to prove $\gcd(a,\gcd(b, c)) = \gcd(\gcd(a, b), c)$?
How do we know c divides a in the third sentence?
Jan
26
comment How to prove $\gcd(a,\gcd(b, c)) = \gcd(\gcd(a, b), c)$?
#4 seems false. How does it follow from the definition of GCD? If d is a prime factor X common to both a and gcd(b,c), and e is a different prime factor Y common to both a and gcd(b,c), then e will not divide d or vice versa, because they're prime.
Jan
22
comment Partition minimizing maximum of Euler's totient function across terms
It maybe a great idea. I read that the ith primorial multiplied by the ith prime is sparsely totient, and used that to quickly build a list (not all sparse totients, but for rough minimization may be OK). I tried building the partition for $2^{64}$ in the style of Euclid's algorithm for GCD -- I took the biggest number in the list < $2^{64}$ and took the remainder of dividing by it, then took the biggest sparse totient in the list under the remainder and took the remainder of dividing by it, etc. etc. Turns out a linear combination of those sparse totients exactly partitioned it. Coincidence?
Jan
18
revised Partition minimizing maximum of Euler's totient function across terms
added 1 characters in body
Jan
18
revised Partition minimizing maximum of Euler's totient function across terms
clarify N
Jan
18
asked Partition minimizing maximum of Euler's totient function across terms
Jan
10
comment Quick way to iterate multiples of a prime N that are not multiples of primes X, Y, Z, …?
Ah, that makes more sense, thanks.
Jan
10
accepted Quick way to iterate multiples of a prime N that are not multiples of primes X, Y, Z, …?
Jan
8
comment Quick way to iterate multiples of a prime N that are not multiples of primes X, Y, Z, …?
If I understand right, this computes the size of the set of numbers I want to iterate, but it doesn't help with iterating or computing e.g. the 5th number, or am I not thinking hard enough yet?
Jan
7
asked Quick way to iterate multiples of a prime N that are not multiples of primes X, Y, Z, …?
Dec
18
comment Primes in arithmetic progression
Is it common to use plain parens to represent gcd? I'm so used to reading those as tuples.
Dec
16
accepted Progressions with variable density that can be described in constant space?