diff --git a/OOP/Java/Lab/Week3/SeqLadder.java b/OOP/Java/Lab/Week3/SeqLadder.java
new file mode 100644
index 0000000..0d756d5
--- /dev/null
+++ b/OOP/Java/Lab/Week3/SeqLadder.java
@@ -0,0 +1,12 @@
+public class SeqLadder {
+    public static void main(String args[]){
+        int a=0;
+        for(int i = 1; i<5 ; i++){
+            for (int j = 0; j<i; j++){
+                System.out.print(++a+" ");
+            }
+            System.out.println("");
+        }
+    }
+    
+}
diff --git a/OOP/Java/Lab/Week3/SqInvAndSinCalc.java b/OOP/Java/Lab/Week3/SqInvAndSinCalc.java
new file mode 100644
index 0000000..7e269b1
--- /dev/null
+++ b/OOP/Java/Lab/Week3/SqInvAndSinCalc.java
@@ -0,0 +1,31 @@
+import java.util.Scanner;
+public class SqInvAndSinCalc {
+    public static void main(String args[]){
+        Scanner sc = new Scanner(System.in);
+        double sum=0, sinx=0;
+
+        System.out.println("Enter the number of terms you want to check (for both Sine and Sum):");
+        int terms = sc.nextInt();
+
+        for(int i=1; i<=terms ; i++){
+            sum += Math.pow(i,-i);
+        }
+
+        System.out.println("Enter the input in degrees for the Sine function:");
+        double y = sc.nextDouble();
+
+        double x = (y) * (3.1415926 / 180.0);
+        double sinx = x;
+        int n = 1;
+        
+        for (int i = 1; i <= terms; i++) {
+            double term = pow(-1, n) * pow(x, 2 * n + 1) / tgamma(2 * n + 1);
+            sinx += term;
+            n++;
+        }
+
+        System.out.println("The value of Sin("+x+") is: "+sinx);
+
+        System.out.println("The sum is "+sum);
+    }
+}