A130211 Triangle read by rows: matrix product A054522 * A000012.

1, 2, 1, 3, 2, 2, 4, 3, 2, 2, 5, 4, 4, 4, 4, 6, 5, 4, 2, 2, 2, 7, 6, 6, 6, 6, 6, 6, 8, 7, 6, 6, 4, 4, 4, 4, 9, 8, 8, 6, 6, 6, 6, 6, 6, 10, 9, 8, 8, 8, 4, 4, 4, 4, 4, 11, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 12, 11, 10, 8, 6, 6, 4, 4, 4, 4, 4, 4, 13, 12, 12, 12, 12, 12, 12, 12, 12

Offset

1,2

Links

Table of n, a(n) for n=1..87.

Formula

A054522 * A000012 as infinite lower triangular matrices.

T(n,n) = A000010(n).

Example

First few rows of the triangle are:
1;
2, 1;
3, 2, 2;
4, 3, 2, 2;
5, 4, 4, 4, 4;
6, 5, 4, 2, 2, 2;
7, 6, 6, 6, 6, 6, 6;
8, 7, 6, 6, 4, 4, 4, 4;
...

Maple

A130211 := proc(n, k)
    add( A054522(n, j), j=k..n) ;
end proc:
seq(seq(A130211(n, k), k=1..n), n=1..15) ; # R. J. Mathar, Aug 06 2016

Crossrefs

Cf. A000010, A054522, A130212 (product with swapped order), A057660 (row sums).

Sequence in context: A029281 A126792 A097367 * A317207 A102364 A342774

Adjacent sequences: A130208 A130209 A130210 * A130212 A130213 A130214

Keyword

nonn,tabl,easy

Author

Gary W. Adamson, May 17 2007

Status

approved