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%I #13 Oct 27 2014 09:51:04
%S 1,1,0,0,0,0,2,32,368,3984,44304,521606,6564318,88422296,1272704694,
%T 19521035238,318120059458,5491779703870,100150978723568,
%U 1924351621839740,38864316540425434
%N Number of permutations of {1,2,...,n} where adjacent elements differ in value by 3 or more.
%C Equivalently, number of permutations of {1,2,...,n} where elements that differ by 1 in value are neither in positions i and i+1 (adjacent), nor i and i+2.
%e Valid permutations of {1,...,6} are 415263 and 362514.
%Y Cf. A002464 (stride >= 2), A179957 (stride >= 4), A179958 (stride >=5).
%K nonn
%O 0,7
%A Richard Forster (gbrl01(AT)yahoo.co.uk), Apr 11 2007, Apr 26 2007
%E Jul 01 2010: _Zak Seidov_ corrected a(10) and a(11). _R. H. Hardin_ then computed a(12) through a(18).
%E Corrected first term to 1 (was 0).
%E a(0), a(19)-a(20) from _Alois P. Heinz_, Oct 27 2014
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