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.

A152717 Triangle T(n,k) read by rows: T(n,k) = 5^min(k, n-k) = 5^A004197(n,k).

Original entry on oeis.org

1, 1, 1, 1, 5, 1, 1, 5, 5, 1, 1, 5, 25, 5, 1, 1, 5, 25, 25, 5, 1, 1, 5, 25, 125, 25, 5, 1, 1, 5, 25, 125, 125, 25, 5, 1, 1, 5, 25, 125, 625, 125, 25, 5, 1, 1, 5, 25, 125, 625, 625, 125, 25, 5, 1, 1, 5, 25, 125, 625, 3125, 625, 125, 25, 5, 1
Offset: 0

Views

Author

Roger L. Bagula and Gary W. Adamson, Dec 11 2008

Keywords

Comments

Row sums are: {1, 2, 7, 12, 37, 62, 187, 312, 937, 1562, 4687,...}

Examples

			{1},
{1, 1},
{1, 5, 1},
{1, 5, 5, 1},
{1, 5, 25, 5, 1},
{1, 5, 25, 25, 5, 1},
{1, 5, 25, 125, 25, 5, 1},
{1, 5, 25, 125, 125, 25, 5, 1},
{1, 5, 25, 125, 625, 125, 25, 5, 1},
{1, 5, 25, 125, 625, 625, 125, 25, 5, 1},
{1, 5, 25, 125, 625, 3125, 625, 125, 25, 5, 1}
		

Crossrefs

Programs

  • Mathematica
    Clear[a, k, m]; k = 5; a[0] = {1}; a[1] = {1, 1};
    a[n_] := a[n] = Join[{1}, k*a[n - 2], {1}];
    Table[a[n], {n, 0, 10}];
    Flatten[%]

Formula

T(n,k) = 5^min(k, n-k). - Philippe Deléham, Feb 25 2014

Extensions

Better name from Philippe Deléham, Feb 25 2014