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 A098023 #13 Jun 01 2025 18:22:32
%S A098023 34,31,9,8,25,39,22,5,3,22,41,17,20,7,35,18,8,54,98,40,51,16,85,43,79,
%T A098023 77,22,21,62,92,54,14,60,97,53,38,61,91,42,33,19,42,105,9,34,39,117,
%U A098023 28,46,94,264,14,75,94,275,57,155,227,128,99,140,230,94,80,233,459,309,327
%N A098023 M={{0, 1, -1, 1}, {-1, 0, 1, -1}, {1, -1, 0, 1}, {-1, 1, -1, 0}}; a(n) = M*a(n-1)-Sum [a(n-)][[i, i]], {i, 1, 4}]*M/n; a[0]:={{0, 1, 1, 2}, {1, 1, 2, 3}, {1, 2, 3, 5}, {2, 3, 5, 8}}.
%C A098023 These types of matrices are used in Kernel inversion functions in scattering theory.
%D A098023 Roger G. Newton, Scattering Theory of Waves and Particles, McGraw Hill, 1966; p. 254.
%t A098023 (* SO(4) Determinant one 4 X 4 Markov Fredholm-like sequence *) (* page 254 Scattering Theory of Waves and Particles by Roger G. Newton 1966 McGraw Hill*) (* by _Roger L. Bagula_, Sep 09 2004 *) Clear[M, A, x] digits=8; M={{0, 1, -1, 1}, {-1, 0, 1, -1}, {1, -1, 0, 1}, {-1, 1, -1, 0}}; Det[M] A[n_]:=M.A[n-1]-Sum[A[n-1][[i, i]], {i, 1, 4}]*M/n; A[0]:={{0, 1, 1, 2}, {1, 1, 2, 3}, {1, 2, 3, 5}, {2, 3, 5, 8}}; (* flattened sequence of 4 X 4 matrices made with an SO(4) Determinant one Fredholm-like recurrence*) b=Flatten[Table[M.A[n], {n, 1, digits}]] Floor[Abs[b]] Dimensions[b][[1]] ListPlot[b, PlotJoined->True]
%K A098023 nonn,uned
%O A098023 1,1
%A A098023 _Roger L. Bagula_, Sep 09 2004