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.

A187954 Triangle by rows, divisors of odd integers.

Original entry on oeis.org

1, 1, 3, 1, 0, 5, 1, 0, 0, 7, 1, 3, 0, 0, 9, 1, 0, 0, 0, 0, 11, 1, 0, 0, 0, 0, 0, 13, 1, 3, 5, 0, 0, 0, 0, 15, 1, 0, 0, 0, 0, 0, 0, 0, 17, 0, 0, 0, 0, 0, 0, 0, 0, 19, 1, 3, 0, 7, 0, 0, 0, 0, 0, 0, 21
Offset: 0

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Author

Gary W. Adamson, Mar 16 2011

Keywords

Comments

Row sums = A008438: (1, 4, 6, 8, 13, 12, 14,...)

Examples

			First few rows of the triangle =
1
1, 3
1, 0, 5
1, 0, 0, 7
1, 3, 0, 0, 9
1, 0, 0, 0, 0, 11
1, 0, 0, 0, 0, 0, 13
1, 3, 5, 0, 0, 0, 0, 15
1, 0, 0, 0, 0, 0, 0, 0, 17
1, 0, 0, 0, 0, 0, 0, 0, 0, 19
1, 3, 0, 7, 0, 0, 0, 0, 0, 0, 21
1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 23
1, 0, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 25
1, 3, 0, 0, 9, 0, 0, 0, 0, 0, 0, 0, 0, 27
...
Example: Row 4 = (1, 3, 0, 0, 9) since the divisors of 9 are (1, 3, and 9).
		

Crossrefs

Formula

Let A = A114000 and B = a diagonalized variant of the odd integers ((1, 3, 5, 7, 9,...) as the right diagonal and the rest zeros). The triangle = A*B as infinite lower triangular matrices.