This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A080009 #17 Apr 16 2024 03:22:10
%S A080009 1,1,2,4,11,26,56,127,288,660,1500,3401,7729,17565,39930,90735,206176,
%T A080009 468536,1064750,2419661,5498621,12495505,28395889,64529315,146642077,
%U A080009 333242093,757288191,1720927502,3910785158,8887207808,20196062308
%N A080009 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={2}.
%D A080009 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 A080009 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 A080009 <a href="/index/Rec#order_10">Index entries for linear recurrences with constant coefficients</a>, signature (1,1,2,3,5,0,1,-1,-1,-1).
%F A080009 a(n) = a(n-1)+a(n-2)+2*a(n-3)+3*a(n-4)+5*a(n-5)+a(n-7)-a(n-8)-a(n-9)-a(n-10).
%F A080009 G.f.: -(x^5+x^3-1)/(x^10+x^9+x^8-x^7-5*x^5-3*x^4-2*x^3-x^2-x+1)
%t A080009 LinearRecurrence[{1,1,2,3,5,0,1,-1,-1,-1},{1,1,2,4,11,26,56,127,288,660},40] (* _Harvey P. Dale_, Nov 20 2021 *)
%Y A080009 Cf. A002524-A002529, A072827, A072850-A072856, A079955-A080014.
%K A080009 nonn
%O A080009 0,3
%A A080009 _Vladimir Baltic_, Feb 10 2003