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.

A106314 Triangle T(n,k) composed of the squares min(n,k)^2.

Original entry on oeis.org

1, 1, 1, 1, 4, 1, 1, 4, 4, 1, 1, 4, 9, 4, 1, 1, 4, 9, 9, 4, 1, 1, 4, 9, 16, 9, 4, 1, 1, 4, 9, 16, 16, 9, 4, 1, 1, 4, 9, 16, 25, 16, 9, 4, 1, 1, 4, 9, 16, 25, 25, 16, 9, 4, 1
Offset: 1

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Author

Gary W. Adamson, Apr 28 2005

Keywords

Examples

			Replacing each term in A003983 by its square, we get:
{1},
{1, 1},
{1, 4, 1},
{1, 4, 4, 1},
{1, 4, 9, 4, 1},
{1, 4, 9, 9, 4, 1},
{1, 4, 9, 16, 9, 4, 1},
{1, 4, 9, 16, 16, 9, 4, 1},
{1, 4, 9, 16, 25, 16, 9, 4, 1},
{1, 4, 9, 16, 25, 25, 16, 9, 4, 1},
{1, 4, 9, 16, 25, 36, 25, 16, 9, 4, 1}
		

Crossrefs

Cf. A003983, A106314, A005993 (row sums).

Programs

  • Mathematica
    Clear[p, n, i];
    p[x_, n_] = Sum[x^i*If[i ==Floor[n/2] && Mod[n, 2] == 0, 0, If[i <= Floor[n/2], 2*i + 1, -(2*(n - i) + 1)]], {i, 0, n}]/(1 - x);
    Table[CoefficientList[FullSimplify[p[x, n]], x], {n, 1, 11}];
    Flatten[%]

Formula

T(n,k) = A003983(n,k)^2.

Extensions

Additional comments from Roger L. Bagula and Gary W. Adamson, Apr 02 2009