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.

A193857 Mirror of the triangle A193856.

Original entry on oeis.org

1, 5, 1, 19, 8, 1, 65, 43, 11, 1, 211, 194, 76, 14, 1, 665, 793, 422, 118, 17, 1, 2059, 3044, 2059, 776, 169, 20, 1, 6305, 11191, 9221, 4387, 1283, 229, 23, 1, 19171, 39878, 38854, 22382, 8236, 1970, 298, 26, 1, 58025, 138805, 156440, 106000, 47090
Offset: 0

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Author

Clark Kimberling, Aug 07 2011

Keywords

Comments

A193857 is obtained by reversing the rows of the triangle A193856.

Examples

			First six rows:
1
5.....1
19....8.....1
65....43....11....1
211...194...76....14....1
665...793...422...118...17...1
		

Crossrefs

Cf. A193856.

Programs

  • Mathematica
    z = 10;
    p[n_, x_] := (2 x + 1)^n;
    q[n_, x_] := (x + 1)^n;
    p1[n_, k_] := Coefficient[p[n, x], x^k];
    p1[n_, 0] := p[n, x] /. x -> 0;
    d[n_, x_] := Sum[p1[n, k]*q[n - 1 - k, x], {k, 0, n - 1}]
    h[n_] := CoefficientList[d[n, x], {x}]
    TableForm[Table[Reverse[h[n]], {n, 0, z}]]
    Flatten[Table[Reverse[h[n]], {n, -1, z}]]  (* A193856 *)
    TableForm[Table[h[n], {n, 0, z}]]
    Flatten[Table[h[n], {n, -1, z}]]   (* A193857 *)

Formula

Write w(n,k) for the triangle at A193856. The triangle at A193857 is then given by w(n,n-k).