/* with a for loop */
#include <stdio.h>
int main ()
{
int n; /* loop index */
int tri_num; /* calculated triangular number value */
printf ("TABLE OF TRIANGULAR NUMBERS by 5\n\n"); printf (" n Triangular Number\n"); printf ("--- -----------------\n");
tri_num = 0;
/* use a for loop */
for (n = 5; n <= 100; n = n + 5) /* or n+= 5 */
{
tri_num = (n * (n + 1))/2;
printf (" %d %d\n", n
, tri_num
); }
return (0);
}
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