1,2

Row sums = sigma(n), A000203. Left column = A079247

Triangle read by rows, A051731 * A158948

First few rows of the triangle =

1;

2, 1;

3, 0, 1;

4, 2, 0, 1;

4, 0, 1, 0, 1;

7, 2, 1, 1, 0, 1;

5, 0, 1, 0, 1, 0, 1;

8, 3, 0, 2, 0, 1, 0, 1;

8, 0, 2, 0, 1, 0, 1, 0, 1;

10, 2, 1, 1, 1, 1, 0, 1, 0, 1;

7, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1;

15, 4, 1, 3, 0, 2, 0, 10, 1, 0, 1;

8, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1;

13, 2, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1;

...

Cf. A158948, A000203, A051731

Sequence in context: A127094 A158906 A143239 this_sequence A126988 A130026 A113287

Adjacent sequences: A158948 A158949 A158950 this_sequence A158952 A158953 A158954

nonn,tabl

Gary W. Adamson & Mats Granvik (qntmpkt(AT)yahoo.com), Mar 31 2009