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.

A140822 Triangle T(n,m) = binomial(n,gcd(n,m)) read by rows, 0<=m<=n.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 3, 3, 1, 1, 4, 6, 4, 1, 1, 5, 5, 5, 5, 1, 1, 6, 15, 20, 15, 6, 1, 1, 7, 7, 7, 7, 7, 7, 1, 1, 8, 28, 8, 70, 8, 28, 8, 1, 1, 9, 9, 84, 9, 9, 84, 9, 9, 1, 1, 10, 45, 10, 45, 252, 45, 10, 45, 10, 1
Offset: 0

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Author

Roger L. Bagula and Gary W. Adamson, Jul 16 2008

Keywords

Comments

Row sums are 1, 2, 4, 8, 16, 22, 64, 44, 160, 224, 474,...

Examples

			1;
1, 1;
1, 2, 1;
1, 3, 3, 1;
1, 4, 6, 4, 1;
1, 5, 5, 5, 5, 1;
1, 6, 15, 20, 15, 6, 1;
1, 7, 7, 7, 7, 7, 7, 1;
1, 8, 28, 8, 70, 8, 28, 8, 1;
1, 9, 9, 84, 9, 9, 84, 9, 9, 1;
1, 10, 45, 10, 45, 252, 45, 10, 45, 10, 1;
		

Programs

  • Mathematica
    a = Table[Table[Binomial[n, GCD[n, m]], {m, 0, n}], {n, 0, 10}]; Flatten[a]

Formula

T(n,m) = A007318(n,A109004(n,m)).

Extensions

Offset corrected by R. J. Mathar, Nov 07 2011