10thpentagonalnumber

<-- Enter pentagonal number statement
  

Calculate pentagonal number 10

The formula for pentagonal number n is as follows
Pn  =  n(3n - 1)
  2

Given n = 10, we have:
P10  =  10(3(10) - 1)
  2

P10  =  10(30 - 1)
  2

P10  =  10(29)
  2

P10  =  290
  2

P10 = 145