Data update

Task/Fermat-numbers/PascalABC.NET/fermat-numbers.pas

@@ -0,0 +1,35 @@
+##
+function IsPrime(n: biginteger): boolean;
+begin
+  if (n = 2) or (n = 3) then Result := true
+  else if (n <= 1) or ((n mod 2) = 0) or ((n mod 3) = 0) then Result := false
+  else
+  begin
+    var i := 5bi;
+    Result := False;
+    while i * i < n do
+    begin
+      if (n mod i) = 0 then
+      begin
+        println(i, n div i);
+        exit;
+      end
+      else if (n mod (i + 2)) = 0 then
+      begin
+        println(i + 2, n div (i + 2));
+        exit;
+      end;
+      i += 6;
+    end;
+    Result := True;
+  end;
+end;
+
+function fermat(n: integer) := power(2bi, int64(power(2, n))) + 1;
+
+for var n := 0 to 9 do writeln('F', n, ' = ', fermat(n));
+for var n := 0 to 6 do
+begin
+  write('F', n, ' = ');
+  if isprime(fermat(n)) then println(fermat(n));
+end;