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%I M0393 #30 May 17 2019 16:26:50
%S 0,2,2,108,2028,32870,1213110,46493784,2310521000,137466038346,
%T 9842687925450,832295357128500
%N a(n) = number of special odd permutations of 2*n+1.
%C a(n) is the number of odd permutations, pi(0),...,pi(2*n), of 0,...,2*n such that pi(0) = 0 and p(k) = k + pi(k) (mod 2*n+1), k=0,...,2*n is also a permutation of 0,...,2*n. - _Sean A. Irvine_, Jan 31 2015
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H D. H. Lehmer, <a href="http://dx.doi.org/10.1016/0022-314X(73)90056-5">Some properties of circulants</a>, J. Number Theory 5 (1973), 43-54.
%Y Cf. A003109 (special even permutations), A003110 (total).
%K nonn,more
%O 1,2
%A _N. J. A. Sloane_
%E Name clarified and offset corrected by _Sean A. Irvine_, Jan 31 2015
%E a(8)-a(9) from _Sean A. Irvine_, Jan 31 2015
%E a(10)-a(12) from _Vaclav Kotesovec_, May 17 2019 (using the terms of A003111 and A003112)
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