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bio website giacomodrago.com
location Rome, Italy
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visits member for 2 years, 9 months
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Apr
9
awarded  Popular Question
Sep
8
revised Proving inequality $(a+\frac{1}{a})^2 + (b+\frac{1}{b})^2 \geq \frac{25}{2}$ for $a+b=1$
some latex stuff
Sep
8
suggested suggested edit on Proving inequality $(a+\frac{1}{a})^2 + (b+\frac{1}{b})^2 \geq \frac{25}{2}$ for $a+b=1$
Apr
3
comment Function mapping combinations to natural numbers
Thank you. Thanks to your suggestions I've managed to write a small Java library to deal with combinations.
Apr
3
awarded  Commentator
Apr
3
revised Function mapping combinations to natural numbers
deleted 1 characters in body
Apr
3
accepted Function mapping combinations to natural numbers
Apr
3
comment Function mapping combinations to natural numbers
Thank you! This is exactly what I am looking for and I'm surprised how wrong where my search queries. I'll read the whole Wikipedia article and figure out how to invert $f$. Thanks again.
Apr
3
comment Function mapping combinations to natural numbers
OK, your edit seems more clean and concise but it lacks the fact that $C$ should be the set of all and only combinations of $n$ elements in $A$. It is not just some random set of sets.
Apr
3
comment Function mapping combinations to natural numbers
Absolutely not. The example I provided, thanks to your correction, is now the exact thing I'm looking for. Mapping combinations to natural numbers, respecting a total order (I don't care which one) with no "holes" (condition 3).
Apr
3
revised Function mapping combinations to natural numbers
added 12 characters in body
Apr
3
comment Function mapping combinations to natural numbers
Sorry, my fault (poor formalism). Set of sets. I'll fix the example.
Apr
3
comment Function mapping combinations to natural numbers
I don't mean permutations and I don't limit it to couples. I just mean combinations of $n$ elements of some set.
Apr
3
asked Function mapping combinations to natural numbers
Jan
15
awarded  Critic
Jan
15
comment Does anyone know the name of the following problem?
I don't understand "as many cities as possible": you can always visit N cities, if there's no constraint on the total distance covered by all salesmen (or by a single salesman).
Jan
3
awarded  Autobiographer
Dec
29
revised Question about a program generating palindromic prime numbers
added 28 characters in body
Dec
15
revised Question about a program generating palindromic prime numbers
added 2 characters in body
Dec
15
revised Question about a program generating palindromic prime numbers
deleted 24 characters in body