A143319 Triangle read by rows, A051731 * A143318; 1<=k<=n.

1, 3, -1, 4, -1, -1, 7, -4, 0, 0, 6, -1, -1, -1, -1, 12, -8, -3, 1, 1, 1, 8, -1, -1, -1, -1, -1, -1, 15, -11, 0, 0, 0, 0, 0, 0, 13, -5, -5, 0, 0, 0, 0, 0, 0, 18, -10, -3, -3, -3, 1, 1, 1, 1, 1, 12, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 28, -27, -7, 4, 4, 4, 0, 0, 0, 0, 0, 0

Offset

1,2

Comments

Left border = sigma(n), A000203.

Right border = mu(n) A008683.

Row sums = d(n), A000005.

Links

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

Example

First few rows of the triangle =
   1;
   3, -1;
   4, -1, -1;
   7, -4,  0,  0;
   6, -1, -1, -1, -1;
  12, -8, -3, -1, -1, -1;
   8, -1, -1, -1, -1, -1, -1;
  ...

Crossrefs

Cf. A000005, A000203, A008683, A051731, A143318.

Sequence in context: A334466 A127057 A143355 * A078011 A010285 A159878

Adjacent sequences: A143316 A143317 A143318 * A143320 A143321 A143322

Keyword

tabl,sign

Author

Gary W. Adamson, Aug 07 2008

Extensions

a(69) = -7 corrected by Georg Fischer, Jun 10 2023

Status

approved