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

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

0,5

Comments

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

Links

Table of n, a(n) for n=0..65.

Formula

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

Example

{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}

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[%]

Crossrefs

Cf. A004197, A144464, A152714, A152716.

Sequence in context: A237888 A286462 A046607 * A071856 A242133 A144221

Adjacent sequences: A152714 A152715 A152716 * A152718 A152719 A152720

Keyword

nonn,easy,tabl

Author

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

Extensions

Better name from Philippe Deléham, Feb 25 2014

Status

approved