1,4

Left border = (1, 1, 2, 2, 3, 3,...) Row sums = (1, 2, 5, 11, 25, 56, 126,...) = A006054 such that row n = A006054(n+2).

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

Triangle read by rows, A * B, where A = an infinite lower triangular matrix with A008619: (1, 1, 2, 2, 3, 3,...) in every column. B = an infinite lower triangular matrix with A008619 as the main diagonal: (1, 2, 5, 11, 25, 56, 126,...) and the rest zeros.

First few rows of the triangle =

1;

1, 1;

2, 1, 2;

2, 2, 2, 5;

3, 2, 4, 5, 11;

3, 3, 4, 10, 11, 25;

4, 3, 6, 10, 22, 25, 56;

4, 4, 6, 15, 22, 50, 56, 126;

5, 4, 8, 15, 33, 50, 112, 126, 283;

...

A006054, Cf. A008619

Sequence in context: A058762 A029252 A094876 this_sequence A073610 A085693 A067995

Adjacent sequences: A144156 A144157 A144158 this_sequence A144160 A144161 A144162

nonn,tabl

Gary W. Adamson (qntmpkt(AT)yahoo.com), Sep 12 2008