1,4

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

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

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;

...

Cf. A126988, A054533

Sequence in context: A093101 A082469 A088151 this_sequence A152196 A024375 A025075

Adjacent sequences: A159903 A159904 A159905 this_sequence A159907 A159908 A159909

tabl,sign

Gary W. Adamson (qntmpkt(AT)yahoo.com), Apr 25 2009