Example: Generate Series 1,3,6,10,15... in C

// Generate Series 1,3,6,10,15...
#include <stdio.h>

int main() {
    // Step 1: Declare variables for the limit, current series term, and incrementer
    int N;             // User-defined limit
    int current_term = 1; // Starts with the first term of the series
    int increment = 2; // The value to add to the current_term, starts with 2 (1 + 2 = 3)

    // Step 2: Prompt the user to enter the limit N
    printf("Enter the upper limit (N): ");
    scanf("%d", &N);

    printf("Series up to %d: ", N);

    // Step 3: Loop to generate and print the series
    // Continue as long as the current_term does not exceed N
    while (current_term <= N) {
        // Step 3a: Print the current term
        printf("%d", current_term);

        // Step 3b: Add a comma and space if it's not the last term to be printed
        // This check prevents an extra comma at the end
        if (current_term + increment <= N) {
            printf(", ");
        }
        
        // Step 3c: Calculate the next term
        current_term += increment; // Add the current increment to get the next term

        // Step 3d: Increment the incrementer for the next iteration
        increment++; // The increment itself increases by 1 each time (2, then 3, then 4...)
    }
    printf("\n"); // Print a newline at the end for clean output

    return 0;
}