A152716 Triangle T(n,k) read by rows: T(n,k) = 4^min(k, n-k) = 4^A004197(n,k).

1, 1, 1, 1, 4, 1, 1, 4, 4, 1, 1, 4, 16, 4, 1, 1, 4, 16, 16, 4, 1, 1, 4, 16, 64, 16, 4, 1, 1, 4, 16, 64, 64, 16, 4, 1, 1, 4, 16, 64, 256, 64, 16, 4, 1, 1, 4, 16, 64, 256, 256, 64, 16, 4, 1, 1, 4, 16, 64, 256, 1024, 256, 64, 16, 4, 1

Offset

0,5

Comments

Row sums are: {1, 2, 6, 10, 26, 42, 106, 170, 426, 682, 1706,...} = A061547(n+2).

Links

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

Formula

T(n,k) = 4^min(k, n-k). - Philippe Deléham, Feb 25 2014

T(n,k) = A144464(n,k)^2. - Philippe Deléham, Feb 26 2014

Example

{1},
{1, 1},
{1, 4, 1},
{1, 4, 4, 1},
{1, 4, 16, 4, 1},
{1, 4, 16, 16, 4, 1},
{1, 4, 16, 64, 16, 4, 1},
{1, 4, 16, 64, 64, 16, 4, 1},
{1, 4, 16, 64, 256, 64, 16, 4, 1},
{1, 4, 16, 64, 256, 256, 64, 16, 4, 1},
{1, 4, 16, 64, 256, 1024, 256, 64, 16, 4, 1}

Mathematica

Clear[a, k, m]; k = 4; 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, A152717.

Sequence in context: A174093 A204028 A106314 * A298575 A326039 A183374

Adjacent sequences: A152713 A152714 A152715 * A152717 A152718 A152719

Keyword

nonn,easy,tabl

Author

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

Extensions

Better name by Philippe Deléham, Feb 25 2014

Status

approved