what is the next term of 13, 9, 5, 1

Question

Please help with number patern on 13, 9, 5, 1

Answer 1

The sequence is :

 

Term

   1         13 - 4*0 = 13

   2         13 - 4*1 =  9

   3         13 - 4*2 =  5

   4         13 - 4*3 =  1

   5         13 - 4*4 = -3

  ...

   n         13 - 4(n-1); n=1, 2, 3, ...

Answer 2

Four is being subtracted each time.

13 - 4 = 9

9 - 4 = 5

5 - 4 = 1