11,2,3,4,5,6:7{(integers)}:integers|[natural|counting] numbers 21,2,3,5,8,13:21{(Fibonacci)}:Fibonacci{ seq{ence}| numbers} 31,2,4,8,16,32:64{(powers of 2)}:powers of 2|2[**|^]n 41,2,6,24,120,720:5040{(factorials)}:factorials|n! 51,3,5,7,9,11:13{(odd nos.)}:odd [integ|numb]ers 61,3,6,10,15,21:28{(triangular)}:triangular{ numbers}|C(n,2) 71,3,9,27,81:243{(powers of 3)}:powers of 3|3[**|^]n 81,4,9,16,25:36{(squares)}:squares|n[**|^]2 91,4,16,64:256{(powers of 4)}:powers of 4|4[**|^]n 101,5,25,125:625{(powers of 5)}:powers of 5|5[**|^]n 111,8,27,64,125:216{(cubes)}:cubes|n[**|^]3 122,3,5,7,11,13:17{(primes)}:prime[ number]s 132,4,6,8,10,12:14{(even nos.)}:even [integ|numb]ers|multiples of 2|2n 143,6,9,12,15:18{(3n)}:multiples of 3|3n 15