a(n){return(n<2)?0:4*a(n-1)+a(n-2)+2;}

#include <stdio.h>

int main()
{
	printf("n\tsum\n");
	for (int i = 1; i < 10; i++)
	{
	  printf("%d\t%d\n", i, a(i));
	}
	printf("\n");
	for (int i = 9; i > 0; i--)
	{
	  printf("%d\t%d\n", i, a(i));
	}
}