Mersenne primes: Difference between revisions
Added D
m (→{{header|Kotlin}}: Replaced 'shiftLeft' function with more idiomatic 'shl' infix function introduced in v1.2.) |
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end repeat
</lang>
=={{header|D}}==
Simplest thing that could possibly work. Using better primality tests will allow for more results to be calculated in a reasonable amount of time.
<lang D>import std.bigint;
import std.stdio;
bool isPrime(BigInt bi) {
if (bi < 2) return false;
if (bi % 2 == 0) return bi == 2;
if (bi % 3 == 0) return bi == 3;
auto test = BigInt(5);
while (test * test < bi) {
if (bi % test == 0) return false;
test += 2;
if (bi % test == 0) return false;
test += 4;
}
return true;
}
void main() {
auto base = BigInt(2);
for (int pow=1; pow<32; pow++) {
if (isPrime(base-1)) {
writeln("2 ^ ", pow, " - 1");
}
base *= 2;
}
}</lang>
{{out}}
<pre>2 ^ 2 - 1
2 ^ 3 - 1
2 ^ 5 - 1
2 ^ 7 - 1
2 ^ 13 - 1
2 ^ 17 - 1
2 ^ 19 - 1
2 ^ 31 - 1</pre>
=={{header|Kotlin}}==
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