What Comes Next?

1x1=1, 3x3=9, 5x5=25, 7x7=49, 9x9=81 Multiplying using odd number 1, 3, 5, 7, 9 with the same number

By subtracting the given sequence by 1 it will be

$1-1\quad ,\quad 9-1\quad ,\quad 25-1\quad ,\quad 49-1$

$0\quad ,\quad 8\quad ,\quad 24\quad ,\quad 48$

$0\times 2\quad ,\quad 2\times 4\quad ,\quad 4\times 6\quad ,\quad 6\times 8$

The next number - 1 = $(6+2)\times (8+2)\quad =\quad 80$

So the answer is $\boxed{81}$

1^2,3^2,5^2,7^2,9^2.........

There should have been one more given to be able to tell if it was sequential odd numbers squared, or sequential prime numbers squared.

1,9,25,49

difference between 1 and 9 is 8 difference between 9 and 25 is 16 difference between 25 and 49 is 24

The pattern continues with adding the next multiple of 8... 32 Thus the answer is 81.

Interesting that you most everyone else dealt with them as squares of odd numbers.

Square of odd numbers, Startingfrom 1. ;1^2=1; 3^2=9; 5^2=25; 7^2=49; 9^2=81.

This problem is wrongly posed. The sequence is composed of the squares of odd numbers, but all the numbers are also prime, so 121 is an equally good answer. The formulation of the problem is not well-constrained.