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.

A177443 Triangle, row sums = A007729; derived from the generator for A002487, Stern's diatomic series.

Original entry on oeis.org

1, 2, 0, 3, 1, 0, 3, 2, 0, 0, 3, 3, 2, 0, 0, 3, 3, 4, 0, 0, 0, 3, 3, 6, 1, 0, 0, 0, 3, 3, 6, 2, 0, 0, 0, 0, 3, 3, 6, 3, 3, 0, 0, 0, 0, 3, 3, 6, 3, 6, 0, 0, 0, 0, 0, 3, 3, 6, 3, 9, 2, 0, 0, 0, 0, 0, 3, 3, 6, 3, 9, 4, 0, 0, 0, 0, 0, 0, 3, 3, 6, 3, 9, 6, 3
Offset: 0

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Author

Gary W. Adamson, May 08 2010

Keywords

Comments

Rows apparently tend to 3 * nonzero terms of Stern's diatomic series; i.e.,
3 * (1, 1, 2, 1, 3, 2, 3, 1, 4, 3, 5, 2, 5,...) = (3, 3, 6, 3, 9, 6, 9, 3, 12,...)
Row sums = A007729: (1, 2, 4, 5, 8, 10, 13, 14, ...)

Examples

			First few rows of the triangle =
1;
2, 0;
3, 1, 0;
3, 2, 0, 0;
3, 3, 2, 0, 0;
3, 3, 4, 0, 0, 0;
3, 3, 6, 1, 0, 0, 0;
3, 3, 6, 2, 0, 0, 0, 0;
3, 3, 6, 3, 3, 0, 0, 0, 0;
3, 3, 6, 3, 6, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 2, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 4, 0, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 6, 3, 0, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 6, 6, 0, 0, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 6, 9, 1, 0, 0, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 6, 9, 2, 0, 0, 0, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 6, 9, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 6, 9, 3, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0;
3, 3, 6, 3, 9, 6, 9, 3, 12, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0;
...
		

Crossrefs

Formula

Triangle read by rows, Q*R*S; where Q = an infinite lower triangular matrix with all 1's, R = the generator for A002487, and S = a diagonalized variant of A002487 (nonzero terms of A002487 as the right diagonal and the rest zeros). R, the generator for A002487 is an irregular lower triangular matrix with (1, 1, 1, 0, 0, 0,...) in each column; but each successive column for k>0 is shifted down twice from the previous column.