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.

A159906 Triangle read by rows, A126988 * A054533.

Original entry on oeis.org

1, 1, 1, 2, -1, 2, 2, 0, 0, 2, 4, -1, -1, -1, 4, 2, 0, 2, -1, 1, 2, 6, -1, -1, -1, -1, -1, 6, 4, 0, 0, 0, 0, 0, 0, 4, 6, -3, 3, 0, 0, -3, 0, 0, 6, 4, 2, -1, -3, 4, -1, 1, -1, 1, 4, 10, -1, -1, -1, -1, -1, -1, -1, -1, -1, 10, 4, -4, 4, 2, 2, 0, 0, -2, 0, 2, 0, 4
Offset: 1

Views

Author

Gary W. Adamson, Apr 25 2009

Keywords

Comments

Row sums = n, right and left borders = A000012, phi(n).

Examples

			First few rows of the triangle =
1;
1,...1;
2,..-1,...2;
2,...0,...0,...2;
4,..-1,..-1,..-1,...4;
2,...0,...2,..-1,...1,...2;
6,..-1,..-1,..-1,..-1,..-1,...6;
4,...0,...0,...0,...0,...0,...0,...4;
6,..-3,...3,...0,...0,..-3,...0,...0,...6;
4,...2,..-1,..-3,...4,..-1,...1,..-1,...1,...4;
10,.-1,..-1,..-1,..-1,..-1,..-1,..-1,..-1,..-1,...10;
4,..-4,...4,...2,...2,...0,...0,..-2,...0,...2,....0,...4;
12,.-1,..-1,..-1,..-1,..-1,..-1,..-1,..-1,..-1,...-1,..-1,...12;
6,...4,..-1,..-3,..-1,..-3,...6,..-1,...1,..-1,....1,...1,....1,...6;
8,..-7,...5,..-2,...8,..-2,...1,...1,..-2,..-4,....1,..-2,....1,...1,...8;
8,...0,...0,...0,...0,...0,...0,...0,...0,...0,....0,...0,....0,...0,...0,...8;
...
		

Crossrefs

Formula

Triangle read by rows, A126988 * A054533, where A054533 = the lower half of the Ramanujan sum table.

Extensions

a(29) split and more terms from Georg Fischer, May 29 2023