Neighbour primes: Difference between revisions
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Found 20 neighbour primes up to 500 |
Found 20 neighbour primes up to 500 |
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</pre> |
</pre> |
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=={{header|AppleScript}}== |
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<lang applescript>on isPrime(n) |
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if (n < 6) then return ((n > 1) and (n is not 4)) |
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if ((n mod 2 = 0) or (n mod 3 = 0) or (n mod 5 = 0)) then return false |
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repeat with i from 7 to (n ^ 0.5) div 1 by 30 |
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if (n mod i = 0) or (n mod (i + 4) = 0) or (n mod (i + 6) = 0) or (n mod (i + 10) = 0) or ¬ |
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(n mod (i + 12) = 0) or (n mod (i + 16) = 0) or (n mod (i + 22) = 0) or (n mod (i + 24) = 0) then ¬ |
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return false |
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end repeat |
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return true |
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end isPrime |
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on neighbourPrimes(max) |
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set output to {} |
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repeat with p from 3 to max by 2 |
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if (isPrime(p)) then |
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set q to p + 2 |
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repeat until (isPrime(q)) |
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set q to q + 2 |
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end repeat |
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if (isPrime(p * q + 2)) then set end of output to p |
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end if |
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end repeat |
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return output |
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end neighbourPrimes |
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neighbourPrimes(499)</lang> |
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{{output}} |
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<lang applescript>{3, 5, 7, 13, 19, 67, 149, 179, 229, 239, 241, 269, 277, 307, 313, 397, 401, 419, 439, 487}</lang> |
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=={{header|AWK}}== |
=={{header|AWK}}== |
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<lang AWK> |
<lang AWK> |
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