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%I #24 Apr 16 2024 03:21:35
%S 1,1,1,2,4,9,15,25,46,84,156,280,501,909,1647,2990,5408,9773,17695,
%T 32033,58000,104976,189968,343860,622409,1126617,2039201,3690898,
%U 6680644,12092173,21887215,39616409,71706406,129790404,234923948
%N Number of permutations satisfying -k<=p(i)-i<=r and p(i)-i not in I, i=1..n, with k=2, r=3, I={-1,2}.
%D D. H. Lehmer, Permutations with strongly restricted displacements. Combinatorial theory and its applications, II (Proc. Colloq., Balatonfured, 1969), pp. 755-770. North-Holland, Amsterdam, 1970.
%H Vladimir Baltic, <a href="http://pefmath.etf.rs/vol4num1/AADM-Vol4-No1-119-135.pdf">On the number of certain types of strongly restricted permutations</a>, Applicable Analysis and Discrete Mathematics Vol. 4, No 1 (2010), 119-135
%H K. Edwards and M. A. Allen, <a href="http://dx.doi.org/10.1016/j.dam.2015.02.004">Strongly restricted permutations and tiling with fences</a>, Discrete Applied Mathematics, Volume 187, 31 May 2015, Pages 82-90.
%H <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,1,1,4,-1,1,0,-1,-1).
%F a(n) = a(n-1)+a(n-3)+a(n-4)+4*a(n-5)-a(n-6)+a(n-7)-a(n-9)-a(n-10).
%F G.f.: -(x^5-1)/(x^10+x^9-x^7+x^6-4*x^5-x^4-x^3-x+1).
%t LinearRecurrence[{1,0,1,1,4,-1,1,0,-1,-1},{1,1,1,2,4,9,15,25,46,84},40] (* _Harvey P. Dale_, Jun 18 2013 *)
%Y Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014.
%K nonn
%O 0,4
%A _Vladimir Baltic_, Feb 10 2003
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