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A123642 n! - 2^n. 3
0, -1, -2, -2, 8, 88, 656, 4912, 40064, 362368, 3627776, 39914752, 478997504, 6227012608, 87178274816, 1307674335232, 20922789822464, 355687427964928, 6402373705465856, 121645100408307712, 2432902008175591424, 51090942171707342848, 1124000727777603485696 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Difference between the number of rows in the truth tables for circuit designs involving n variables and the order of S_n (the symmetric group on n symbols).

REFERENCES

Audu, M. S. and Ibrahim, A. A., (2006) Discrete Mathematics With Applications (in preparation)

Ibrahim, A. A., (2006) A stable Variety of Cayley Graphs For Efficient Interconnection Networks (submitted)

Ibrahim, A. A. and Audu, M. S., (2005) Some Group theoretic Properties of Certain class of (123) and (132)-avoiding patterns of certain numbers; An enumeration Scheme. African Journal of Natural Sciences,  Afri. J. Nat. Sci., 8: 79-84.

LINKS

Table of n, a(n) for n=0..22.

FORMULA

a(n) = A000142(n) - A000079(n). - Michel Marcus, Aug 12 2013

(-n+3)*a(n) +(n^2-n-4)*a(n-1) -2*(n-1)*(n-2)*a(n-2)=0. - R. J. Mathar, Oct 20 2015

MATHEMATICA

Table[n!-2^n, {n, 0, 40}] (* Vladimir Joseph Stephan Orlovsky, May 19 2011 *)

PROG

(Sage) [factorial(n)-2^n for n in xrange(0, 23)] # Zerinvary Lajos, Oct 27 2009

CROSSREFS

Sequence in context: A012659 A009448 A012410 * A007848 A102895 A270555

Adjacent sequences:  A123639 A123640 A123641 * A123643 A123644 A123645

KEYWORD

sign

AUTHOR

Aminu Alhaji Ibrahim, Oct 04 2006

STATUS

approved

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Last modified September 25 18:20 EDT 2017. Contains 292499 sequences.