|
|
A118231
|
|
Triangle, read by rows, equal to the matrix square of triangle A118229.
|
|
2
|
|
|
1, -2, 1, -2, 0, 1, 4, -2, -2, 1, -2, 0, 0, 0, 1, 2, 1, 1, -2, -2, 1, 4, 0, -2, 0, -2, 0, 1, -6, 1, 6, -2, 1, 0, -2, 1, -4, 0, 1, 0, 3, 0, -2, 0, 1, 6, -1, -6, 4, -1, -2, 4, -2, -2, 1, -4, 0, 3, 0, 1, 0, -2, 0, 0, 0, 1, 4, 0, -3, -1, -1, 1, 2, 1, 1, -2, -2, 1, 14, 0, -7, 0, -7, 0, 6, 0, -2, 0, -2, 0, 1, -14, 0, 3, 1, 10, 0, -4, -2, 3, 0, 1, 0, -2, 1
(list;
table;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,2
|
|
COMMENTS
|
Describes the sequence transformation of triangle A118229 iterated twice. Also equals the matrix inverse of triangle A118233.
|
|
LINKS
|
|
|
EXAMPLE
|
Triangle begins:
1;
-2, 1;
-2, 0, 1;
4,-2,-2, 1;
-2, 0, 0, 0, 1;
2, 1, 1,-2,-2, 1;
4, 0,-2, 0,-2, 0, 1;
-6, 1, 6,-2, 1, 0,-2, 1;
-4, 0, 1, 0, 3, 0,-2, 0, 1;
6,-1,-6, 4,-1,-2, 4,-2,-2, 1;
-4, 0, 3, 0, 1, 0,-2, 0, 0, 0, 1;
4, 0,-3,-1,-1, 1, 2, 1, 1,-2,-2, 1;
14, 0,-7, 0,-7, 0, 6, 0,-2, 0,-2, 0, 1; ...
|
|
PROG
|
(PARI) T(n, k)=if(n<k || k<0, 0, (matrix(n, n, r, c, if(r>=c, if(gcd(r-c+1, c)==1, 1, 0)))^-2)[n, k])
|
|
CROSSREFS
|
|
|
KEYWORD
|
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|