question

int index = 0;
Array sequence =[1,3,5,6,7,8,9,12,15];
for (int cnt = 0; cnt < 1000; cnt++)// any value that increase would do it
{  index = cnt%sequence.length+1;// modulus operator 
   // over the increased value by the length of the array
   print(sequence[index]); // 1,3,5,6,7,8,9,12,15 several times
}