Smallest number k such that k+2^m is composite for all m less than k: Difference between revisions

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 An embedded version as, judging by the size of numbers involved, Wren-CLI (using BigInt) will be too slow for this.
-Brute force approach - takes a smidge over 2 seconds.
+Brute force approach - takes a smidge under 2 seconds.
 <lang ecmascript>import "./gmp" for Mpz
@@ Line 45: / Line 45: @@
     if (k == 1) return false
     for (m in 1...k) {
-        var n = (Mpz.one << m) + k
+        var n = Mpz.one.lsh(m).add(k)
         if (n.probPrime(15) > 0) return false
     }