cp's OEIS Frontend

A007711 Number of unreformed permutations of {1,...,n}.

%I A007711 M3546 #31 Jan 17 2018 19:08:47
%S A007711 0,1,4,18,105,636,4710,38508,352902,3563297,39467081,475326930,
%T A007711 6198134207,86912048471,1305146666727,20897040866280
%N A007711 Number of unreformed permutations of {1,...,n}.
%D A007711 A. M. Bersani, "Reformed permutations in Mousetrap and its generalizations", preprint MeMoMat n. 15/2005.
%D A007711 R. K. Guy and R. J. Nowakowski, "Mousetrap," in D. Miklos, V. T. Sos and T. Szonyi, eds., Combinatorics, Paul Erdős is Eighty. Bolyai Society Math. Studies, Vol. 1, pp. 193-206, 1993.
%D A007711 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A007711 A. M. Bersani, <a href="http://www.dmmm.uniroma1.it/~bersani/mousetrap.html">On the game Mousetrap</a>.
%H A007711 A. M. Bersani, <a href="http://www.emis.de/journals/INTEGERS/papers/kg1/kg1.Abstract.html">Reformed Permutations in mousetrap and its generalizations</a>, INTEGERS, 10 (2010), #G01.
%H A007711 R. K. Guy and R. J. Nowakowski, <a href="/A002467/a002467_1.pdf">Mousetrap</a>, Preprint, Feb 10 1993 [Annotated scanned copy]
%H A007711 R. K. Guy and R. J. Nowakowski, <a href="http://www.jstor.org/stable/2975171">Mousetrap</a>, Amer. Math. Monthly, 101 (1994), 1007-1010.
%F A007711 a(n) = n! - A007709(n). - _Sean A. Irvine_, Jan 17 2018
%e A007711 For n=3, the 4 unreformed permutations are 123, 231, 312, 213, so a(3)=4. Also 132->123, 321->213 are reformable.
%Y A007711 Cf. A007709, A007712, A055459, A067950.
%K A007711 nonn,more
%O A007711 1,3
%A A007711 _N. J. A. Sloane_
%E A007711 More terms from Kok Seng Chua (chuaks(AT)ihpc.nus.edu.sg), Mar 06 2002
%E A007711 2 more terms from Alberto M. Bersani (bersani(AT)dmmm.uniroma1.it), Feb 07 2007
%E A007711 One more term from Alberto M. Bersani (bersani(AT)dmmm.uniroma1.it), Feb 24 2008
%E A007711 a(1) corrected by _Joerg Arndt_, Dec 24 2014