diff --git a/semana23/index.ts b/semana23/index.ts
new file mode 100644
index 0000000..31dd5a4
--- /dev/null
+++ b/semana23/index.ts
@@ -0,0 +1,53 @@
+//Exercício 01
+//A
+function printNumbers(n: number) {
+  if (n >= 0) {
+    printNumbers(n - 1);
+    console.log(n);
+  }
+}
+//B
+const printNumbersDescendingOrder = (n: number) => {
+  if (n >= 0) {
+    console.log(n);
+    printNumbers(n - 1);
+  }
+};
+
+//Exercício 02
+export const calculateSum = (n: number, acc: number = 0): number => {
+  if (n >= 0) {
+    return acc;
+  }
+  return calculateSum(n - 1, acc + n);
+};
+//GABARITO 02
+export const calculateSumTo = (n: number, acc: number = 0): number => {
+  if (n === 0) {
+    return acc;
+  }
+  return calculateSumTo(n - 1, acc + n);
+};
+
+// Exemplos de uso:
+console.log(calculateSumTo(3));
+console.log(calculateSumTo(10));
+console.log(calculateSumTo(100));
+
+//Exercício 03
+export const calculateSumToRefactored = (n: number): number => {
+  let sum = 0;
+  for (let i = 0; i <= n; i++) {
+    sum += 1;
+  }
+
+  return sum;
+};
+
+// Exercício 04
+export const printArray = (arr: number[], i: number = arr.length - 1) => {
+  if (i >= 0) {
+    printArray(arr, i - 1);
+    console.log(`Elemento ${i}: `, arr[i]);
+  }
+};