Lucas-Lehmer test: Difference between revisions

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  Finding Mersenne primes in M[2..2147483647]:
  M2 M3 M5 M7 M13 M17 M19 M31 M61 M89 M107 M127 M521 M607 M1279 M2203 M2281 M3217 M4253 M4423 M9689 M9941 M11213
+=={{header|Modula-3}}==
+Modula-3 uses L as the literal for <tt>LONGINT</tt>.
+<lang modula3>MODULE LucasLehmer EXPORTS Main;
+IMPORT IO, Fmt, Long;
+PROCEDURE Mersenne(p: CARDINAL): BOOLEAN =
+  VAR
+    s := 4L;
+    m := Long.Shift(1L, p) - 1L; (* 2^p - 1 *)
+  BEGIN
+    IF p = 2 THEN
+      RETURN TRUE;
+    ELSE
+      FOR i := 3 TO p DO
+        s := (s * s - 2L) MOD m;
+      END;
+      RETURN s = 0L;
+    END;
+  END Mersenne;
+BEGIN
+  FOR i := 2 TO 63 DO
+    IF Mersenne(i) THEN
+      IO.Put("M" & Fmt.Int(i) & " ");
+    END;
+  END;
+  IO.Put("\n");
+END LucasLehmer.</lang>
+Output:
+<pre>M2 M3 M5 M7 M13 M17 M19 M31 </pre>
 =={{header|Oz}}==