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 A354228 #26 Oct 31 2024 13:32:20
%S A354228 1,6,58,578,5766,57810,580310,5829538,58575686,588641522,5915670070,
%T A354228 59451845314,597489270438,6004768803090,60348023150742,
%U A354228 606498938168290,6095328830488582,61258206225329970,615646518692614390,6187263150038580994
%N A354228 Number of partitions of the multigraph G_n (defined below) into "strokes".
%C A354228 Here G_n = {V_n, E_n}, V_n = {v_1, v_2, ..., v_n}, E_n = {e_1, e_2, ..., e_{n-1}, f_1, f_2, ..., f_{n-1}}. For all i, e_i = f_i = v_iv_{i+1} although e_i and f_i are considered distinct.
%C A354228 Given an undirected multigraph G = (V,E) with labeled edges, its partition into strokes is a collection of directed edge-disjoint paths (viewed as sets of directed edges) on V such that (i) union of any two paths is not a path; (ii) union of corresponding undirected paths is E.
%H A354228 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (13,-22,-88,112).
%F A354228 For n >= 6, a(n) = 13*a(n-1) - 22*a(n-2) - 88*a(n-3) + 112*a(n-4).
%F A354228 O.g.f.: x * (1-2*x)^2 * (1 - 3*x - 14*x^2) / (1 - 13*x + 22*x^2 + 88*x^3 - 112*x^4).
%t A354228 CoefficientList[Series[x (1-2x)^2(1-3x-14x^2)/(1-13x+22x^2+88x^3-112x^4),{x,0,20}],x] (* or *) LinearRecurrence[{13,-22,-88,112},{0,1,6,58,578,5766},30] (* _Harvey P. Dale_, Oct 31 2024 *)
%Y A354228 Previously A131519 was thought to be this sequence.
%Y A354228 Cf. A131518, A131520.
%K A354228 nonn
%O A354228 1,2
%A A354228 _Yasutoshi Kohmoto_ and _Max Alekseyev_, Jul 18 2022