25, 49 and 121
Numbers having exactly three factors are the squares of prime numbers. Examples of these numbers greater than 100 are 121, 169, 289, 361, 529, 841, etc.
11 x 11 = 121
11 x 11 = 121
1, 11, and 121. (This number has an odd number of factors because it is a perfect square: 11 * 11 = 121.)
21 The pattern is 121, 12321, 1234321
The first thing to notice is that all the numbers in the sequence are square numbers. 25=5x5 36=6x6 49=7x7 64=8x8 81=9x9 So the next three numbers to be squared are 10, 11 and 12. 10x10=100 11x11=121 12x12=144 Thus, the next three numbers in the sequence are 100, 121, 144 The equation for the sequence is (n+4)2
25 36 49 64 81 100 121 144
The numbers are 120, 121 and 122.
There appears to be no discernible pattern for these numbers, other than them increasing in arbitrary multiples of 6.
112 = 121 and 122 = 144.
121, 169, 289
364
25, 49 and 121
111
121, 125 and 128.
The highest common factor of the three numbers is 11