diff --git a/app.js b/app.js
index ad9a93a7..ee929ced 100644
--- a/app.js
+++ b/app.js
@@ -1 +1,28 @@
 'use strict';
+//function fib(n){
+//    if (n===0){
+//        return 0;
+//    }
+//    else if (n===1){
+//        return 1;
+//    }
+//    return fib(n - 1) + fib(n - 2);
+//}
+
+const memo = new Map();
+memo.set(0,0);
+memo.set(1,0);
+memo.set(2,1);
+
+function trib(n){
+    if (memo.has(n)){
+        return memo.get(n);
+    }
+    const value = trib(n-1) + trib(n-2) + trib(n-3);
+    memo.set(n, value);
+    return value;
+}
+const length=40;
+for (let i = 0; i <= length; i++) {
+    console.log(trib(i));
+  }
\ No newline at end of file