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Given the following text description, write Python code to implement the functionality described.
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Description:
Centered triangular number
function for Centered Triangular number ; Formula to calculate nth Centered Triangular number ; Driver Code ; For 3 rd Centered Triangular number ; For 12 th Centered Triangular number

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Python Code:
def Centered_Triangular_num(n ) : 
	 return(3 * n * n + 3 * n + 2 ) // 2 
  if __name__== ' __main __' : 
	 n = 3 
 print(Centered_Triangular_num(n ) ) 
 n = 12 
 print(Centered_Triangular_num(n ) ) 
 
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