More Problems

• Create a program to determine if a number is a valid ISBN.
• Write a program to calculate the sum of the first n squares.
• Implement a function to check if a number is a Catalan number.
• Create a program to calculate the area of an ellipse given its axes.
• Write a program to find the largest prime number less than n.
• Implement a function to calculate the average of the first n integers.
• Create a program to find the sum of all odd digits in a number.
• Write a program to check if a string is a valid JSON.