2ndnonagonalnumber

<-- Enter nonagonal number statement
  

Calculate nonagonal number 2

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

Given n = 2, we have:
N2  =  2(7(2) - 5)
  2

N2  =  2(14 - 5)
  2

N2  =  2(9)
  2

N2  =  18
  2

N2 = 9