C++ :

#include<bits/stdc++.h>
using namespace std;
int n; 
int main()
{
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=i;j++)
			cout<<j;
		cout<<endl;
	}
   return 0;
}

Pascal :

var n,i,j:longint;
begin
  readln(n);
  for i:=1 to n do
      begin
        for j:=1 to i do
            begin
              write(j);
            end;
        writeln;
      end;
end.