Simple Pyramid In C - c

Question

the code I've written creates a pyramid with given input. I need the first part Incrementing by 2, but the code written does not really Incrementing by 2. Aprrechiate any help.
Code:
int main() {
int i, j, n, a, rows;
printf("Enter a Number: ");
scanf("%d", &rows);
printf("\nPattern for %d:\n\n", rows);
for (i = 0; i <= rows; i++) {
printf("%d | ", i);
for(a = 2; a <= i; a+=2) {
printf("%d ", a);
}
for (j = 0; j <= i; j++) {
if (j == i){
printf("%d ", j);
}
}
for(n = 1; n < i; n++){
printf("%d ", j);
j++;
}
printf("\n");
}
return 0;
}
Needed Output:
0 | 0
1 | 0 1
2 | 0 2 2 3
3 | 0 2 4 3 4 5
4 | 0 2 4 6 4 5 6 7
5 | 0 2 4 6 8 5 6 7 8 9
6 | 0 2 4 6 8 10 6 7 8 9 10 11
Current Output:
0 | 0
1 | 1
2 | 2 2 3
3 | 2 3 4 5
4 | 2 4 4 5 6 7
5 | 2 4 5 6 7 8 9
6 | 2 4 6 6 7 8 9 10 11

Answer 1

I had to add an extra if condition for i = 0 because it was not fitting in the pattern I figured out. I have done it in just 2 loops instead of you using 3 loops.
Here is the brief explanation. Comment on this answer if you don't understand the code still, I will add a detailed explanation.
Case i = 0 is a special case and it is handled separately using an if.
for i > 0, you can notice that there are 2 series in parallel
even numbers always starting from 0 and if you count them then they are equal to value of i in that row.
another series whose first number is the value of i in that row and it also has number of elements equal to value of i in that row.
That's why in both the loops that handle the series they are run from 0 till i-1.
I hope it helps you and please accept as correct answer if it did.
#include <stdio.h>
int main() {
int i, j, n, a, b, c, rows;
printf("Enter a Number: ");
scanf("%d", &rows);
printf("\nPattern for %d:\n\n", rows);
for (i = 0; i <= rows; i++) {
if(i == 0){
printf("0 | 0\n");
continue;
}
printf("%d | ", i);
// For handling the even number series
for(a = 0, b = 0; a < i; a++, b+=2) {
printf("%d ", b);
}
// For handling the incremental series
for (j = 0, c = i; j < i; j++, c++) {
printf("%d ", c);
}
printf("\n");
}
return 0;
}

Answer 2

You try to overcomplicate simple task.
void pyramid(int rows)
{
for(int row = 0; row < rows; row++)
{
for(int even = 0; even < row * 2; even += 2)
{
printf("%d ", even);
}
if(row == 0) printf("%d ", row);
else
{
for(int remain = row; remain < row * 2; remain++)
{
printf("%d ", remain);
}
}
printf("\n");
}
}
https://godbolt.org/z/cdWqsq