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.

A158106 A triangle of structure called "Polynomial on residue classes" (PORC).

Original entry on oeis.org

1, 2, 2, 5, 5, 5, 14, 14, 15, 15, 51, 51, 67, 76, 77, 267, 267, 504, 633, 684, 731, 2328, 2328, 9310, 9310, 34297, 62440, 113147
Offset: 1

Views

Author

Roger L. Bagula, Mar 12 2009

Keywords

Examples

			Triangle begins:
  {1},
  {2, 2},
  {5, 5, 5},
  {14, 14, 15, 15},
  {51, 51, 67, 76, 77},
  {267, 267, 504, 633, 684, 731},
  {2328, 2328, 9310, 9310, 34297, 62440, 113147}
		

References

  • Marcus Du Sautoy, Symmetry: A Journey into the Patterns of Nature,Harper (March 11, 2008),page 96,pp. 141-143 ( and the work of Christopher Voll)

Programs

  • Mathematica
    p[x_, 1] := 1;
    p[x_, 2] := 2;
    p[x_, 3] := 5;
    p[x_, 4] := If[x <= 2, 14, 15];
    p[x_, 5] := If[x <= 2, 51, If[x == 3, 67, 61 + 2*x + 2 * GCD[x - 1, 3] + GCD[x - 1, 4]]];
    p[x_, 6] := If[x <= 2, 267, If[x == 3, 504, 3*x^2 + 39*x + 344 + 24 *GCD[x - 1, 3] + 11* GCD[x - 1, 4] + 2* GCD[x - 1, 5]]];
    p[x_, 7] := If[x <= 2, 2328, If[x >= 3 and x<5, 9310, If[x == 5, 34297,
    3*x^5 + 12*x^4 + 44*x^3 + 170*x^2 + 707* x + 2455 + (4*x^2 + 44*x + 291) *GCD[x - 1, 3] + (x^2 + 19*x + 135) * GCD[x - 1, 4] + (3*x + 31)* GCD[x - 1, 5] + 4* GCD[ x - 1, 7] + 5* GCD[x - 1, 8] + GCD[x - 1, 9]]]];
    a = Table[Table[p[x, n], {x, 1, n}], {n, 1, 7}];
    Flatten[a]