C++ Program For Sum of Natural Numbers Using Recursion Last Updated : 23 Jun, 2023 Comments Improve Suggest changes Like Article Like Report Natural numbers include all positive integers from 1 to infinity. It does not include zero (0). Given a number n, find the sum of the first n natural numbers. To calculate the sum, we will use the recursive function recur_sum(). Examples: Input: 3Output: 6Explanation: 1 + 2 + 3 = 6 Input: 5Output: 15Explanation: 1 + 2 + 3 + 4 + 5 = 15 The Sum of Natural Numbers Using Recursion Below is a C++ program to find the sum of natural numbers up to n using recursion: C++ // C++ program to find the sum // of natural numbers up to n // using recursion #include <iostream> using namespace std; // Returns sum of first // n natural numbers int recurSum(int n) { if (n <= 1) return n; return n + recurSum(n - 1); } // Driver code int main() { int n = 5; cout << recurSum(n); return 0; } Output15 Comment More info K kartik Follow Improve Article Tags : C++ Programs C++ C++ Basic Programs Explore C++ BasicsIntroduction to C++3 min readData Types in C++7 min readVariables in C++4 min readOperators in C++9 min readBasic Input / Output in C++5 min readControl flow statements in Programming15+ min readLoops in C++7 min readFunctions in C++8 min readArrays in C++8 min readCore ConceptsPointers and References in C++5 min readnew and delete Operators in C++ For Dynamic Memory5 min readTemplates in C++8 min readStructures, Unions and Enumerations in C++3 min readException Handling in C++11 min readFile Handling through C++ Classes8 min readMultithreading in C++8 min readNamespace in C++5 min readOOP in C++Object Oriented Programming in C++8 min readInheritance in C++10 min readPolymorphism in C++5 min readEncapsulation in C++4 min readAbstraction in C++4 min readStandard Template Library(STL)Standard Template Library (STL) in C++3 min readContainers in C++ STL3 min readIterators in C++ STL10 min readC++ STL Algorithm Library3 min readPractice & ProblemsC++ Interview Questions and Answers1 min readC++ Programming Examples4 min read Like