A143355 Triangle read by rows: A051731 * A010766 as infinite lower triangular matrices.

1, 3, 1, 4, 1, 1, 7, 3, 1, 1, 6, 2, 1, 1, 1, 12, 5, 3, 1, 1, 1, 8, 3, 2, 1, 1, 1, 1, 15, 7, 3, 3, 1, 1, 1, 1, 13, 5, 4, 2, 1, 1, 1, 1, 1, 18, 8, 4, 3, 3, 1, 1, 1, 1, 1, 12, 5, 3, 2, 2, 1, 1, 1, 1, 1, 1, 28, 13, 8, 5, 3, 3, 1, 1, 1, 1, 1, 1

Offset

1,2

Comments

Left column = sigma(n), A000203.

Row sums = A143356: (1, 4, 56, 12, 11, 23, 17,...).

Links

Table of n, a(n) for n=1..78.

Example

First few rows of the triangle =
1;
3, 1;
4, 1, 1;
7, 3, 1, 1;
6, 2, 1, 1, 1;
12, 5, 3, 1, 1, 1;
8, 3, 2, 1, 1, 1, 1;
15, 7, 3, 3, 1, 1, 1, 1;
...

Crossrefs

Cf. A000203, A010766, A051731, A143356.

Sequence in context: A130314 A334466 A127057 * A143319 A078011 A010285

Adjacent sequences: A143352 A143353 A143354 * A143356 A143357 A143358

Keyword

nonn,tabl

Author

Gary W. Adamson, Aug 10 2008

Extensions

a(72) split by Georg Fischer, May 29 2023

Status

approved