Factorial Table


Factorial & Double Factorial : āĻĢ⧇āĻ•ā§āϟ⧰āĻŋāϝāĻŧ⧇āϞ āφ⧰⧁ āĻĄāĻžāĻŦāϞ āĻĢ⧇āĻ•ā§āϟ⧰āĻŋāϝāĻŧ⧇āϞ


Factorial ( n! )


Definition: Factorial of a non-negative integer n is the product of all positive integers from 1 to n. āĻāϟāĻž āĻ…āĻ‹āĻŖāĻžāĻ¤ā§āĻŽāĻ• āĻĒā§‚ā§°ā§āĻŖāϏāĻ‚āĻ–ā§āϝāĻž n ā§° āĻĢ⧇āĻ•ā§āϟ⧰āĻŋāϝāĻŧ⧇āϞ āĻš’āϞ 1 ā§° āĻĒā§°āĻž n āϞ⧈ āϏāĻ•āϞ⧋ āϧāύāĻžāĻ¤ā§āĻŽāĻ• āĻĒā§‚ā§°ā§āĻŖāϏāĻ‚āĻ–ā§āϝāĻžā§° āϗ⧁āĻŖāĻĢāϞāĨ¤


n! = n × (n-1) ×â‹¯× 1


Double Factorial ( n!! )


Definition: Double factorial of n is the product of numbers ≤ n that have the same parity (even or odd) as n.


n* ā§° āĻĄāĻžāĻŦāϞ āĻĢ⧇āĻ•ā§āϟ⧰āĻŋāϝāĻŧ⧇āϞ āĻš’āϞ n ā§° āϏ⧈āϤ⧇ āĻāϕ⧇ āϧ⧰āĻŖā§° (āĻœā§‹ā§°āĻž āĻŦāĻž āĻŦāĻŋāĻœā§‹ā§°āĻž) āϏāĻ‚āĻ–ā§āϝāĻžāĻŦā§‹ā§°ā§° āϗ⧁āĻŖāĻĢāϞāĨ¤


Special Rules | āĻŦāĻŋāĻļ⧇āώ āύāĻŋāϝāĻŧāĻŽ : 0! = 1, 0!! = 1, 1!! = 1


Factorial Values



  • 1! = 1

  • 2! = 2

  • 3! = 6

  • 4! = 24

  • 5! = 120

  • 6! = 720

  • 7! = 5,040

  • 8! = 40,320

  • 9! = 362,880

  • 10! = 3,628,800

  • 11! = 39,916,800

  • 12! = 479,001,600

  • 13! = 6,227,020,800

  • 14! = 87,178,291,200

  • 15! = 1,307,674,368,000


Double Factorial Values


Even Numbers (āĻœā§‹ā§°āĻž āϏāĻ‚āĻ–ā§āϝāĻž)



  • 2!! = 2

  • 4!! = 8

  • 6!! = 48

  • 8!! = 384

  • 10!! = 3,840

  • 12!! = 46,080

  • 14!! = 645,120


Odd Numbers (āĻŦāĻŋāĻœā§‹ā§°āĻž āϏāĻ‚āĻ–ā§āϝāĻž)



  • 1!! = 1

  • 3!! = 3

  • 5!! = 15

  • 7!! = 105

  • 9!! = 945

  • 11!! = 10,395

  • 13!! = 135,135

  • 15!! = 2,027,025


 Examples | āωāĻĻāĻžāĻšā§°āĻŖ


Ex 1: Factorial


5! = 5 × 4 × 3 × 2 × 1 = 120


Ex 2: Double Factorial (Even)


8!! = 8 × 6 × 4 × 2 = 384


Ex 3: Double Factorial (Odd)


9!! = 9 × 7 × 5 × 3 × 1 = 945