%I A000565 M5227 N2275
%S A000565 31,696,5823,29380,108933,327840,848380,1958004,4130895,8107024,
%T A000565 14990889,26372124,44470165,72305160,113897310,174496828,260846703,
%U A000565 381480456,547057075,770735316,1068589557,1460069392,1968505152,2621661540
%N A000565 Number of discordant permutations.
%D A000565 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A000565 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 
               (includes this sequence).
%D A000565 S. Plouffe, Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques 
               Conjectures, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 
               1992.
%D A000565 J. Riordan, Discordant permutations, Scripta Math., 20 (1954), 14-23.
%H A000565 S. Plouffe, <a href="http://www.lacim.uqam.ca/%7Eplouffe/articles/MasterThesis.pdf">
               Approximations de S\'{e}ries G\'{e}n\'{e}ratrices et Quelques Conjectures</
               a>, Dissertation, Universit\'{e} du Qu\'{e}bec \`{a} Montr\'{e}al, 
               1992.
%H A000565 S. Plouffe, <a href="http://www.lacim.uqam.ca/%7Eplouffe/articles/FonctionsGeneratrices.pdf">
               1031 Generating Functions and Conjectures</a>, Universit\'{e} du 
               Qu\'{e}bec \`{a} Montr\'{e}al, 1992.
%F A000565 G.f.: -x^7(12x^7-6x^6+88x^5-131x^4-548x^3-1123x^2-448x-31)/((1-x)^8).
%F A000565 a(n)=243/560n^7-243/16n^6+3591/16n^5-28737/16n^4+82257/10n^3-81931/4n^2+151931/
               7n, for n>6.
%p A000565 pp := n - >243/560*n^7 - 243/16*n^6 + 3591/16*n^5 - 28737/16*n^4 + 82257/
               10*n^3 - 81931/4*n^2 + 151931/7*n; seq(pp(n), n=0..30);
%p A000565 A000565:=-(12*z**7-6*z**6-131*z**4+88*z**5-1123*z**2-548*z**3-31-448*z)/
               (z-1)**8; [Conjectured by S. Plouffe in his 1992 dissertation.]
%Y A000565 Sequence in context: A020983 A020981 A006097 this_sequence A014930 A061252 
               A096049
%Y A000565 Adjacent sequences: A000562 A000563 A000564 this_sequence A000566 A000567 
               A000568
%K A000565 nonn
%O A000565 3,1
%A A000565 N. J. A. Sloane (njas(AT)research.att.com).
%E A000565 More terms, formulae and Maple code from Barbara Haas Margolius (margolius(AT)math.csuohio.edu) 
               2/17/01