A266365 Number of possible plugboard settings for a WWII German Enigma Cipher Machine with n cables.
1, 325, 44850, 3453450, 164038875, 5019589575, 100391791500, 1305093289500, 10767019638375, 53835098191875, 150738274937250, 205552193096250, 102776096548125, 7905853580625, 0, 0, 0
Offset: 0
Keywords
References
- Andrew Hodges, Alan Turing: the Enigma, Princeton University Press, 2014.
Links
- A. Ray Miller, The Cryptographic Mathematics of Enigma, Cryptologia, 19 (1995), 65-80.
- Kalika Prasad and Munesh Kumari, A review on mathematical strength and analysis of Enigma, arXiv:2004.09982 [cs.CR], 2020.
- Tony Sale, Counting the Possible Plugboard Setting, Codes and Ciphers, Enigma.
Crossrefs
Cf. A181386.
Programs
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Mathematica
Table[26!/((26 - 2 n)! n! 2^n), {n, 0, 16}]
Formula
a(n) = 26! / ((26 - 2n)! n! 2^n) = C(2,26,n) (see A181386).
Comments