2,4

Triangle A004070 is generated from B * A. Rows sums of A104726 = A001629 starting with n=2: 1, 2, 5, 10, 20, 38, 71...(Fibonacci numbers convolved with themselves).

Triangle is extracted from A * B, A = [1; 0, 1; 0, 1, 1; 0, 0, 2, 1; 0, 0, 1, 3, 1;...]; B = [1; 1, 1; 1, 1, 1...], both infinite lower triangular matrices with the rest of the terms zeros. "A": (1, 0, 1, 0, 1, 1, 0, 0, 2, 1...) = A026729.

First few rows of the triangle are

1;

1, 1;

2, 2, 1;

3, 3, 3, 1;

5, 5, 5, 4, 1;

8, 8, 8, 8, 5, 1;

13, 13, 13, 13, 12, 6, 1;

21, 21, 21, 21, 21, 17, 7, 1;

...

Cf. A001629, A026729, A004070, A000071.

Adjacent sequences: A104723 A104724 A104725 this_sequence A104727 A104728 A104729

Sequence in context: A011373 A117915 A097094 this_sequence A091224 A112182 A112209

nonn,uned,tabl

Gary W. Adamson (qntmpkt(AT)yahoo.com), Mar 20 2005