A143319 - OEIS

%I #8 Jun 10 2023 08:09:30

%S 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,

%T -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,

%U 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

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

%C Left border = sigma(n), A000203.

%C Right border = mu(n) A008683.

%C Row sums = d(n), A000005.

%e First few rows of the triangle =

%e    1;

%e    3, -1;

%e    4, -1, -1;

%e    7, -4,  0,  0;

%e    6, -1, -1, -1, -1;

%e   12, -8, -3, -1, -1, -1;

%e    8, -1, -1, -1, -1, -1, -1;

%e   ...

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

%K tabl,sign

%O 1,2

%A _Gary W. Adamson_, Aug 07 2008

%E a(69) = -7 corrected by _Georg Fischer_, Jun 10 2023