Ultra useful primes: Difference between revisions
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m (→{{header|ALGOL 68}}: tiny tweak) |
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<pre> |
<pre> |
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1 3 5 15 5 59 159 189 569 105 |
1 3 5 15 5 59 159 189 569 105 |
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</pre> |
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=={{header|Go}}== |
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{{libheader|GMP(Go wrapper)}} |
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<lang go>package main |
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import ( |
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"fmt" |
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big "github.com/ncw/gmp" |
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) |
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var two = big.NewInt(2) |
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func a(n uint) int { |
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one := big.NewInt(1) |
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p := new(big.Int).Lsh(one, 1 << n) |
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p.Sub(p, one) |
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for k := 1; ; k += 2 { |
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if p.ProbablyPrime(15) { |
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return k |
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} |
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p.Sub(p, two) |
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} |
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} |
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func main() { |
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fmt.Println(" n k") |
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fmt.Println("----------") |
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for n := uint(1); n < 14; n++ { |
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fmt.Printf("%2d %d\n", n, a(n)) |
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} |
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}</lang> |
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{{out}} |
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<pre> |
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n k |
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---------- |
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1 1 |
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2 3 |
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3 5 |
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4 15 |
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5 5 |
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6 59 |
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7 159 |
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8 189 |
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9 569 |
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10 105 |
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11 1557 |
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12 2549 |
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13 2439 |
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</pre> |
</pre> |
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