Talk:Q49008
Autodescription — prime number (Q49008)
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- Report on constraint conformation of “prime number” claims and statements. Constraints report for items data
- Parent classes (classes of items which contain this one item)
- prime number (Q49008)
- square-free integer (Q50706)
- positive integer (Q28920044)
- non-negative integer (Q28920052) (@)→
- positive real number (Q3176558)
- natural number (Q21199)
- →(@) non-negative integer (Q28920052)
- square-free element (Q2509291)
- positive integer (Q28920044)
- prime element (Q240651)
- square-free integer (Q50706)
- prime number (Q49008)
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prime number⟩ on wikidata tree visualisation (external tool)(depth=1) - Generic queries for classes
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circular defining formula[edit]
As "defining formula" is given phi(p) = p-1. ("phi" is not explained...) Although one can define phi without explicitly using the notion of prime, the standard formula to compute it uses the prime factorization. In that sense the definition is circular. One can avoid the factorization and count the smaller integers n with GCD(n,p) = 1. GCD means "greatest common divisor". It would be better to use the simpler defining formula which also corresponds to the very definition, namely: number of divisors sigma_0(p) = 2. (Other less unambiguous notations for sigma_0() include d() and tau().) This would be more elementary and efficient ("number of divisors" instead of "numbers of smaller numbers with greatest common divisor one") and more logical. I'm new to wikidata so I don't know whether it's OK to add a new "defining formula". – MFH (talk) 12:35, 16 August 2020 (UTC)
- I agree and changed, please check. --Infovarius (talk) 21:08, 8 September 2020 (UTC)