Add libsive.js

libsive.js

@@ -0,0 +1,23 @@
+const isPrime = num => {
+    for(let i = 2, s = Math.sqrt(num); i <= s; i++) {
+        if(num % i === 0) return false;
+    }
+    return num > 1;
+}
+
+function sive(siveTo) {
+    let primes = []
+    siveTo = Number(siveTo)
+
+    for (var i = 1; i < siveTo; i++) {
+        if (isPrime(i)) {
+                primes.push(i)
+        }
+    }
+
+    if (isPrime(siveTo)) {
+        primes.push(siveTo)
+    }
+
+    return primes
+}