Lucky number of Euler: Difference between revisions
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There are only six lucky numbers of Euler: | There are only six lucky numbers of Euler: | ||
<section begin="list"/>[[2]], [[3]], [[5]], [[11]], [[17]], [[41]] [[Oeis:A014556|View list | <section begin="list"/>[[2]], [[3]], [[5]], [[11]], [[17]], [[41]] [[Oeis:A014556|View list on OEIS]]<section end="list"/> | ||
==Polynomial values== | |||
The table should eventually go up to <math>n = 40</math>. It is not yet completed. | |||
Note that among the primes till 100, the only primes that are ''not'' covered in this table at least once are [[79]] and [[89]]. | |||
{| class="sortable" border="1" | |||
! <math>n</math> !! <math>n^2 - n</math> !! Polynomial value <math>n^2 - n + 2</math> !! Polynomial value <math>n^2 - n + 3</math> !! Polynomial value <math>n^2 - n + 5</math> !! Polynomial value <math>n^2 - n + 11</math> !! Polynomial value <math>n^2 - n + 17</math> !! Polynomial value <math>n^2 - n + 41</math> | |||
|- | |||
| 1 || 0 || [[2]] || [[3]] || [[5]] || [[11]] || [[17]] || [[41]] | |||
|- | |||
| 2 || 2 || N/A || [[5]] || [[7]] || [[13]] || [[19]] || [[43]] | |||
|- | |||
| 3 || 6 || N/A || N/A || [[13]] || [[19]] || [[23]] || [[47]] | |||
|- | |||
| 4 || 12 || N/A || N/A || [[17]] || [[23]] || [[29]] || [[53]] | |||
|- | |||
| 5 || 20 || N/A || N/A || N/A || [[31]] || [[37]] || [[61]] | |||
|- | |||
| 6 || 30 || N/A || N/A || N/A || [[41]] || [[47]] || [[71]] | |||
|- | |||
| 7 || 42 || N/A || N/A || N/A || [[53]] || [[59]] || [[83]] | |||
|- | |||
| 8 || 56 || N/A || N/A || N/A || [[67]] || [[73]] || [[97]] | |||
|- | |||
| 9 || 72 || N/A || N/A || N/A || [[83]] || [[89]] || [[113]] | |||
|- | |||
| 10 || 90 || N/A || N/A || N/A || [[101]] || [[107]] || [[131]] | |||
|- | |||
| 11 || 110 || N/A || N/A || N/A || N/A || [[127]] || [[151]] | |||
|- | |||
| 12 || 132 || N/A || N/A || N/A || N/A || [[149]] || [[173]] | |||
|} | |||
Latest revision as of 22:26, 15 January 2012
Definition
A lucky number of Euler is a prime number such that the polynomial:
takes prime number values for .
This condition is equivalent to the condition that the ring of integers in be a unique factorization domain, or equivalently, the class number of the field be equal to one.
Occurrence
There are only six lucky numbers of Euler:
2, 3, 5, 11, 17, 41 View list on OEIS
Polynomial values
The table should eventually go up to . It is not yet completed.
Note that among the primes till 100, the only primes that are not covered in this table at least once are 79 and 89.
| Polynomial value | Polynomial value | Polynomial value | Polynomial value | Polynomial value | Polynomial value | ||
|---|---|---|---|---|---|---|---|
| 1 | 0 | 2 | 3 | 5 | 11 | 17 | 41 |
| 2 | 2 | N/A | 5 | 7 | 13 | 19 | 43 |
| 3 | 6 | N/A | N/A | 13 | 19 | 23 | 47 |
| 4 | 12 | N/A | N/A | 17 | 23 | 29 | 53 |
| 5 | 20 | N/A | N/A | N/A | 31 | 37 | 61 |
| 6 | 30 | N/A | N/A | N/A | 41 | 47 | 71 |
| 7 | 42 | N/A | N/A | N/A | 53 | 59 | 83 |
| 8 | 56 | N/A | N/A | N/A | 67 | 73 | 97 |
| 9 | 72 | N/A | N/A | N/A | 83 | 89 | 113 |
| 10 | 90 | N/A | N/A | N/A | 101 | 107 | 131 |
| 11 | 110 | N/A | N/A | N/A | N/A | 127 | 151 |
| 12 | 132 | N/A | N/A | N/A | N/A | 149 | 173 |