#include<stdio.h>

int last_number(int row) {
    int l = row + 1;

    return l * (l - 1) / 2;
}

int first_number(int row) {
    return last_number(row) - row + 1;
}

int main() {
    int r = 10;
    int r_first = first_number(r);
    int r_last = last_number(r);

    printf("Linha: %i - Primeiro: %i - Ultimo: %i\n\n", r, r_first, r_last);

    for(int i = r_first; i <= r_last; i++) {
        printf("%i ", i);
    }
}