1,4

Row sums = the Robbins sequence A005130, starting with offset 1: (1, 2, 7, 42, 429,...).

Right and left borders = A160707, the convolution square root of A005130.

Let M = an infinite lower triangular Toeplitz matrix with A160707 in every column: (1, 1, 3, 18, 192, 5472,...); where A160707 = the convolution square root of the Robbins sequence: (1, 2, 7, 42, 429, 7436,...). Let Q = an infinite lower triangular matrix with (1, 1, 3, 18, 192,...) as the main diagonal and the rest zeros. Triangle A160708 = M * Q.

First few rows of the triangle =

1;

1, 1;

3, 1, 3;

18, 3, 3, 18;

192, 18, 9, 18, 192;

3472, 192, 54, 54, 192, 3472;

104964, 3472, 576, 324, 576, 3472, 104964;

5606272, 104964, 10416, 3456, 3456, 10416, 104964, 5306272;

...

Example: row 5 = (192, 18, 9, 18, 192) = (192, 18, 3, 1, 1) * (1, 1, 3, 18, 192); where A005130(5) = 429 = (192 + 18 + 9 + 18 + 192).

Cf. A005130, A160707

Sequence in context: A001351 A143081 A112811 this_sequence A040173 A128777 A067009

Adjacent sequences: A160705 A160706 A160707 this_sequence A160709 A160710 A160711

nonn,tabl

Gary W. Adamson (qntmpkt(AT)yahoo.com), May 24 2009