OFFSET
0,2
COMMENTS
A triangle having similar properties and complementary construction is the dual triangle A121435.
FORMULA
EXAMPLE
Triangle, A121334^-1, begins:
1;
-2, 1;
-2, -4, 1;
-14, 0, -7, 1;
-143, -22, 11, -11, 1;
-1928, -260, -40, 40, -16, 1;
-32219, -3894, -385, -121, 99, -22, 1;
-640784, -70644, -6496, -406, -406, 203, -29, 1;
-14753528, -1502940, -128723, -9583, 259, -1184, 370, -37, 1; ...
Triangle A121412 begins:
1;
1, 1;
3, 1, 1;
18, 4, 1, 1;
170, 30, 5, 1, 1; ...
1;
-7, 1;
7, -7, 1;
-14, 0, -7, 1; ...
1;
-11, 1;
33, -11, 1;
-22, 22, -11, 1;
-143, -22, 11, -11, 1;...
PROG
(PARI) /* Matrix Inverse of A121334 */ {T(n, k)=local(M=matrix(n+1, n+1, r, c, if(r>=c, binomial(r*(r-1)/2+r-c, r-c)))); return((M^-1)[n+1, k+1])}
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Paul D. Hanna, Aug 29 2006
STATUS
approved