cp's OEIS Frontend

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.

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}}.

Original entry on oeis.org

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, 77, 22, 21, 62, 92, 54, 14, 60, 97, 53, 38, 61, 91, 42, 33, 19, 42, 105, 9, 34, 39, 117, 28, 46, 94, 264, 14, 75, 94, 275, 57, 155, 227, 128, 99, 140, 230, 94, 80, 233, 459, 309, 327
Offset: 1

Views

Author

Roger L. Bagula, Sep 09 2004

Keywords

Comments

These types of matrices are used in Kernel inversion functions in scattering theory.

References

  • Roger G. Newton, Scattering Theory of Waves and Particles, McGraw Hill, 1966; p. 254.

Programs

  • Mathematica
    (* 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]