3rdnonagonalnumber

<-- Enter nonagonal number statement
  

Calculate nonagonal number 3

The formula for nonagonal number n is as follows
Nn  =  n(7n - 5)
  2

Given n = 3, we have:
N3  =  3(7(3) - 5)
  2

N3  =  3(21 - 5)
  2

N3  =  3(16)
  2

N3  =  48
  2

N3 = 24