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 A271648 #16 Apr 14 2016 11:22:10
%S A271648 6,119,2279,18042,83921,284428,782795,1859374,3957717,7738336,
%T A271648 14140143,24449570,40377369,64143092,98567251,147171158,214284445,
%U A271648 305160264,426098167,584574666,789381473,1050771420
%N A271648 Number of permutations in S_{2*n+3} containing the pattern 2143...(2n)(2n-1).
%C A271648 This sequence is eventually polynomial.
%D A271648 N. Shar, Experimental methods in permutation patterns and bijective proof, PhD thesis, Rutgers University (2016)
%F A271648 For n >= 2, a(n) = (32/3)*n^6 + 32*n^5 + (80/3)*n^4 + (16/3)*n^3 + 38/3*n^2 + 59/3*n + 13 (conjectured).
%F A271648 Conjectures from _Colin Barker_, Apr 11 2016: (Start)
%F A271648 a(n) = 7*a(n-1)-21*a(n-2)+35*a(n-3)-35*a(n-4)+21*a(n-5)-7*a(n-6)+a(n-7) for n>6.
%F A271648 G.f.: (6+77*x+1572*x^2+4378*x^3+1531*x^4+137*x^5-22*x^6+x^8) / (1-x)^7.
%F A271648 (End)
%F A271648 Remark by _Nathaniel Shar_, Apr 13 2016: The preceding three conjectures are equivalent (provided appropriate initial conditions are specified for the recurrence relation).
%Y A271648 Cf. A217193.
%K A271648 nonn,easy
%O A271648 0,1
%A A271648 _Nathaniel Shar_, Apr 11 2016