OFFSET
1,3
EXAMPLE
First few rows of the triangle are:
1;
-1, 3;
-1, 0, 5;
0, -3, 0, 8;
-1, 0, 0, 0, 9;
1, -3,-5, 0, 0, 15;
...
MAPLE
A018804 := proc(n)
sum(igcd(n, j), j=1..n):
end proc:
A127627 := proc(n, k)
end proc: # R. J. Mathar, Oct 21 2012
CROSSREFS
KEYWORD
AUTHOR
Gary W. Adamson, Jan 20 2007
STATUS
approved