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 infoAdvertise with us Next Article Must Coding Questions - Company-wise K kartik Follow Improve Article Tags : C++ Programs C++ C++ Basic Programs Practice Tags : CPP Similar Reads Interview PreparationInterview Preparation For Software DevelopersMust Coding Questions - Company-wise Must Do Coding Questions - Topic-wiseCompany-wise Practice ProblemsCompany PreparationCompetitive ProgrammingSoftware Design-PatternsCompany-wise Interview ExperienceExperienced - Interview ExperiencesInternship - Interview ExperiencesPractice @GeeksforgeeksProblem of the DayTopic-wise PracticeDifficulty Level - SchoolDifficulty Level - BasicDifficulty Level - EasyDifficulty Level - MediumDifficulty Level - HardLeaderboard !!Explore More...Data StructuresArraysLinked ListStackQueueBinary TreeBinary Search TreeHeapHashingGraphAdvance Data StructuresMatrixStringAll Data StructuresAlgorithmsAnalysis of AlgorithmsSearching AlgorithmsSorting AlgorithmsPattern SearchingGeometric AlgorithmsMathematical AlgorithmsRandomized AlgorithmsGreedy AlgorithmsDynamic ProgrammingDivide & ConquerBacktrackingBranch & BoundAll AlgorithmsProgramming LanguagesCC++JavaPythonC#Go LangSQLPHPScalaPerlKotlinWeb TechnologiesHTMLCSSJavaScriptBootstrapTailwind CSSAngularJSReactJSjQueryNodeJSPHPWeb DesignWeb BrowserFile FormatsComputer Science SubjectsOperating SystemsDBMSComputer NetworkComputer Organization & ArchitectureTOCCompiler DesignDigital Elec. & Logic DesignSoftware EngineeringEngineering MathematicsData Science & MLComplete Data Science CourseData Science TutorialMachine Learning TutorialDeep Learning TutorialNLP TutorialMachine Learning ProjectsData Analysis TutorialTutorial LibraryPython TutorialDjango TutorialPandas TutorialKivy TutorialTkinter TutorialOpenCV TutorialSelenium TutorialGATE CSGATE CS NotesGate CornerPrevious Year GATE PapersLast Minute Notes (LMNs)Important Topic For GATE CSGATE CoursePrevious Year Paper: CS exams Like