1,6

Row sums = A000930 starting with offset 1: (1, 1, 2, 3, 4, 6, 9, 13, 19,...).

Sum of n-th row terms = rightmost term of next row.

Let M = an infinite lower triangular matrix with (1, 1, 0, -1, 0, 1, 0, -1, 0, 1,...) in every column; and X = an infinite lower triangular matrix with A000930 as the main diagonal (offset 1): (1, 1, 2, 3, 4, 6, 9, 13, 19,...) and the rest zeros. Triangle A145580 = M * X.

First few rows of the triangle =

1;

1, 1;

0, 1, 2;

-1, 0, 2, 3;

0, -1, 0, 3, 4;

1, 0, -2, 0, 4, 6;

0, 1, 0, -3, 0, 6, 9;

-1, 0, 2, 0, -4, 0, 9, 13;

0, -1, 0, 3, 0, -6, 0, 13, 19;

1, 0, -2, 0, 4, 0, -9, 0, 19, 28;

...

Row 6 = (1, 0, -2, 0, 4, 6) = termwise products of (1, 0, -1, 0, 1, 1) and (1, 1, 2, 3, 4, 6).

A000930

Sequence in context: A128095 A097854 A161515 this_sequence A144219 A144027 A019591

Adjacent sequences: A145577 A145578 A145579 this_sequence A145581 A145582 A145583

tabl,sign

Gary W. Adamson (qntmpkt(AT)yahoo.com), Oct 13 2008