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.

A193916 Mirror of the triangle A193915.

Original entry on oeis.org

1, 1, 2, 2, 4, 4, 4, 8, 12, 16, 7, 14, 24, 40, 48, 12, 24, 44, 80, 128, 160, 20, 40, 76, 144, 256, 416, 512, 33, 66, 128, 248, 464, 832, 1344, 1664, 54, 108, 212, 416, 800, 1504, 2688, 4352, 5376, 88, 176, 348, 688, 1344, 2592, 4864, 8704, 14080, 17408
Offset: 0

Views

Author

Clark Kimberling, Aug 09 2011

Keywords

Comments

A193916 is obtained by reversing the rows of the triangle A193915.

Examples

			First six rows:
1
1....2
2....4....4
4....8....12...16
7....14...24...40...48
12...24...44...80...128...160
		

Crossrefs

Programs

  • Mathematica
    z = 12;
    p[n_, x_] := Sum[Fibonacci[k + 2]*x^(n - k), {k, 0, n}];
    q[n_, x_] := 2 x*q[n - 1, x] + 1 ; q[0, x_] := 1;
    t[n_, k_] := Coefficient[p[n, x], x^k]; t[n_, 0] := p[n, x] /. x -> 0;
    w[n_, x_] := Sum[t[n, k]*q[n + 1 - k, x], {k, 0, n}]; w[-1, x_] := 1
    g[n_] := CoefficientList[w[n, x], {x}]
    TableForm[Table[Reverse[g[n]], {n, -1, z}]]
    Flatten[Table[Reverse[g[n]], {n, -1, z}]]  (* A193908 *)
    TableForm[Table[g[n], {n, -1, z}]]
    Flatten[Table[g[n], {n, -1, z}]]  (* A193909 *)

Formula

Write w(n,k) for the triangle at A193915. The triangle at A193916 is then given by w(n,n-k).