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.

A124389 A square array of Kolakoski string lengths, read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 3, 5, 1, 1, 1, 1, 7, 5, 7, 1, 1, 1, 1, 9, 17, 7, 9, 1, 1, 1, 1, 17, 25, 31, 9, 11, 1, 1, 1, 1, 25, 61, 49, 49, 11, 13, 1, 1, 1, 1, 43, 109, 145, 81, 71, 13, 15, 1, 1, 1
Offset: 0

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Author

Paul Barry, Oct 30 2006

Keywords

Comments

Rows of square array include A066983,A095342,A095343,A095344. See A066983 for description of Kolakoski strings. Sums of antidiagonals is A124390.

Examples

			Square array begins
1, 1, 1, 1, 1, 1, 1...
1, 1, 1, 3, 3, 7, 9...
1, 1, 1, 5, 5, 17, 25...
1, 1, 1, 7, 7, 31, 49...
1, 1, 1, 9, 9, 49, 81...
1, 1, 1, 11, 11, 71, 121...
1, 1, 1, 13, 13, 97, 169...
As a number triangle, triangle begins
1,
1, 1,
1, 1, 1,
1, 1, 1, 1,
1, 3, 1, 1, 1,
1, 3, 5, 1, 1, 1,
1, 7, 5, 7, 1, 1, 1,
1, 9, 17, 7, 9, 1, 1, 1,
1, 17, 25, 31, 9, 11, 1, 1, 1
		

Formula

Row k of square array has g.f. (1+x-kx^2)/((1+x)(1-x-kx^2))