%I A007060
%S A007060 1,0,8,240,13824,1263360,168422400,30865121280,7445355724800,
%T A007060 2287168006717440,871804170613555200,403779880746418176000,
%U A007060 223346806774106790297600,145427383048755178635264000
%N A007060 Number of ways n couples can sit in a row without any spouses next to 
               each other.
%H A007060 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               CocktailPartyGraph.html">Cocktail Party Graph</a>
%H A007060 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               HamiltonianPath.html">Hamiltonian Path</a>
%F A007060 a(n) = (Pi*BesselI(n+1/2,1)*(-1)^n+BesselK(n+1/2,1))*exp(-1)*(2/Pi)^(1/
               2)*2^n*n! [From Mark van Hoeij (hoeij(AT)math.fsu.edu), Nov 12 2009]
%F A007060 a(n) = (-1)^n*2^n*n!*A000806(n), n>0. [From Vladeta Jovovic (vladeta(AT)eunet.rs), 
               Nov 19 2009]
%F A007060 a(n) = n!*hypergeom([ -n, n+1],[],1/2)*(-2)^n [From Mark van Hoeij (hoeij(AT)math.fsu.edu), 
               Nov 13 2009]
%p A007060 sum((-1)^i*binomial(n,i)*(2^i*abs((2*n-i))!),i=0..n);
%Y A007060 Sequence in context: A134504 A145418 A067360 this_sequence A158263 A115613 
               A085524
%Y A007060 Adjacent sequences: A007057 A007058 A007059 this_sequence A007061 A007062 
               A007063
%K A007060 nonn,easy,nice,new
%O A007060 0,3
%A A007060 David.Roberts.Keeney(AT)directory.Reed.EDU (David Roberts Keeney)
%E A007060 More terms from Michel ten Voorde (seqfan(AT)tenvoorde.org) Apr 11 2001