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.

A143595 Triangle read by rows, A000012 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's); 1<=k<=n.

Original entry on oeis.org

1, 2, 2, 3, 4, 2, 4, 6, 4, 2, 5, 8, 6, 4, 2, 6, 10, 8, 6, 4, 2, 7, 12, 10, 8, 6, 4, 2, 8, 14, 12, 10, 8, 6, 4, 2, 9, 16, 14, 12, 10, 8, 6, 4, 2, 10, 18, 16, 14, 12, 10, 8, 6, 4, 2, 11, 20, 18, 16, 14, 12, 10, 8, 6, 4, 2
Offset: 1

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Author

Gary W. Adamson, Aug 26 2008

Keywords

Comments

Row sums = n^2.
The linear sequence A056944 is more appropriately a triangle, (reversal of A143595).

Examples

			First few rows of the triangle =
1;
2, 2;
3, 4, 2;
4, 6, 4, 2;
5, 8, 6, 4, 2;
6, 10, 8, 6, 4, 2;
7, 12, 10, 8, 6, 4, 2;
...
		

Crossrefs

Cf. A056944.

Formula

Triangle read by rows, A000012 * (an infinite lower triangular matrix with 1's in the first column and the rest 2's); i.e. (1; 1,2; 1,2,2;...). A000012 = an infinite lower triangular matrix with all 1's. 1<=k<=n