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.

A158946 Triangle read by rows, A000012(signed) * A145677 * A000012.

Original entry on oeis.org

1, 1, 1, 2, 1, 2, 2, 2, 1, 3, 3, 2, 3, 1, 4, 3, 3, 2, 4, 1, 5, 4, 3, 4, 2, 5, 1, 6, 4, 4, 3, 5, 2, 6, 1, 7, 5, 4, 5, 3, 6, 2, 7, 1, 8, 5, 5, 4, 6, 3, 7, 2, 8, 1, 9, 6, 5, 6, 4, 7, 3, 8, 2, 9, 1, 10, 6, 6, 5, 7, 4, 8, 3, 9, 2, 10, 1, 11
Offset: 1

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Author

Gary W. Adamson, Mar 31 2009

Keywords

Comments

Row sums = A000982 starting with offset 1: (1, 2, 5, 8, 13, 18, 25,...).

Examples

			First few rows of the triangle =
1;
1, 1;
2, 1, 2;
2, 2, 1, 3;
3, 2, 3, 1, 4;
3, 3, 2, 4, 1, 5;
4, 3, 4, 2, 5, 1, 6;
4, 4, 3, 5, 2, 6, 1, 7;
5, 4, 5, 3, 6, 2, 7, 1, 8;
5, 5, 4, 6, 3, 7, 2, 8, 1, 9;
6, 5, 6, 4, 7, 3, 8, 2, 9, 1, 10;
6, 6, 5, 7, 4, 8, 3, 9, 2, 10, 1, 11;
7, 6, 7, 5, 8, 4, 9, 3, 10, 2, 11, 1, 12;
7, 7, 6, 8, 5, 9, 4, 10, 3, 11, 2, 12, 1, 13;
...
		

Crossrefs

Formula

Triangle read by rows, A000012(signed) * A145677 * A000012. A000012(signed) = an infinite lower triangular matrix with (1,-1,1,-1,...) in every column. A145677 = an infinite lower triangular matrix with all 1's as the left border, right border = (1, 1, 2, 3, 4, 5,...), and the rest zeros.