Code 1: # let’s we have enter the number of line say 5 here

int i,j,pval;
for(i=1;i<=n;i++)
{
printf("%d ",i);pval=i;
for(j=2;j<=i;j++){pval+=n-j+1; cout<<pval<<" ";}
cout<<"\n";
}

Code 2: # Let's we have number N, maximum value to be printed

int i,j;
for(i=1;i*i<=8*N+1;i+=2);
int n,pval;
n=(i-2)/2;
n = n*(n+1)/2==N?n:n+1;
for(i=1;i<=n;i++)
{
(i<=N)&&printf("%d ",i)||1; pval=i;
for(j=2;j<=i;j++){pval+=n-j+1;(pval<=N)&&printf("%d ",pval);}
cout<<"\n";
}