Data commit

Task/Lucas-Lehmer-test/CoffeeScript/lucas-lehmer-test.coffee

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+sorenson = require('sieve').primes  # Sorenson's extensible sieve from task: Extensible Prime Number Generator
+
+# Test if 2^n-1 is a Mersenne prime.
+# assumes that the argument p is prime.
+#
+isMersennePrime = (p) ->
+    if p is 2 then yes
+    else
+        n = (1n << BigInt p) - 1n
+        s = 4n
+        s = (s*s - 2n) % n for _ in [1..p-2]
+        s is 0n
+
+primes = sorenson()
+mersennes = []
+while (p = primes.next().value) < 3000
+    if isMersennePrime(p)
+        mersennes.push p
+
+console.log "Some Mersenne primes: #{"M" + String p for p in mersennes}"