Prime numbers p for which the sum of primes less than or equal to p is prime: Difference between revisions
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(Prime numbers p which sum of prime numbers less or equal to p is prime es FreeBASIC) |
Catskill549 (talk | contribs) (added AWK) |
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Found 21 prime sums of primes below 1000 |
Found 21 prime sums of primes below 1000 |
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</pre> |
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=={{header|AWK}}== |
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<lang AWK> |
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# syntax: GAWK -f PRIME_NUMBERS_P_WHICH_SUM_OF_PRIME_NUMBERS_LESS_OR_EQUAL_TO_P_IS_PRIME.AWK |
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BEGIN { |
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start = 1 |
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stop = 999 |
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for (i=start; i<=stop; i++) { |
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if (is_prime(i)) { |
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sum += i |
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if (is_prime(sum)) { |
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printf("%4d%1s",i,++count%10?"":"\n") |
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} |
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} |
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} |
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printf("\n%d-%d: %d\n",start,stop,count) |
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exit(0) |
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} |
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function is_prime(x, i) { |
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if (x <= 1) { |
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return(0) |
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} |
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for (i=2; i<=int(sqrt(x)); i++) { |
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if (x % i == 0) { |
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return(0) |
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} |
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} |
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return(1) |
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} |
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</lang> |
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{{out}} |
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<pre> |
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2 3 7 13 37 43 281 311 503 541 |
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557 593 619 673 683 733 743 839 881 929 |
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953 |
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1-999: 21 |
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</pre> |
</pre> |
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