%I A000470 M4901 N2101
%S A000470 13,72,595,4096,39078,379760,4181826,49916448,647070333,9035216428,135236990388,
%T A000470 2159812592384,36658601139066,658942295734944,12504663617290908,249823152134646144,
%U A000470 5241223014084306270,115206851288747267148,2647678812396326064043
%N A000470 Number of permutations of an n-sequence discordant with three given permutations
(see reference) in n-5 places.
%D A000470 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences,
Academic Press, 1995 (includes this sequence).
%D A000470 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973
(includes this sequence).
%D A000470 J. Riordan, Discordant permutations, Scripta Math., 20 (1954), 14-23.
%F A000470 a(n) = coefficient of y^5 in sum_0^n sigma_{n, k}(n - k)!(y - 1)^k on
y where the sigma_{n, k} have generating function sigma(t, u)=(1
- 2t^2(u^2) - 2t^2(1 + t)u^3 + 3t^4(u^4))(1 - tu)^( - 1)(1 - (1 +
2t)u - tu^2 + t^3(u^3))^( - 1).
%p A000470 seq(f(n,5), n=5..30); #code for f(n,k) is given in A000440
%Y A000470 Cf. A000500, A000492, A000440, A000476, A000380, A000388.
%Y A000470 Sequence in context: A026916 A106173 A094943 this_sequence A107141 A139849
A139911
%Y A000470 Adjacent sequences: A000467 A000468 A000469 this_sequence A000471 A000472
A000473
%K A000470 nonn
%O A000470 5,1
%A A000470 N. J. A. Sloane (njas(AT)research.att.com).
%E A000470 More terms, formula and Maple code from Barbara Haas Margolius (margolius(AT)math.csuohio.edu)
2/17/01
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