OFFSET
0,2
FORMULA
EXAMPLE
Triangle begins:
.1;
.-2,1;
.3,0,1;
.-8,-4,-4,1;
.15,10,10,0,1;
.-36,-30,-36,-12,-6,1;
.77,70,91,42,21,0,1;
.-192,-184,-256,-152,-96,-24,-8,1;
.459,450,648,432,306,108,36,0,1;
.-1220,-1210,-1780,-1280,-1000,-460,-200,-40,-10,1;
.3201,3190,4741,3542,2926,1540,770,220,55,0,1; ...
PROG
(PARI) {T(n, k)=local(x=X+O(X^(n+2)), y=Y+O(Y^(n+2)), M=matrix(n+1, n+1, r, c, polcoeff(polcoeff(1/(1-x*y)+r*x/((1-x*y)*(1+x+x*y)), r-1, X), c-1, Y))); if(n<k, 0, (M^-1)[n+1, k+1])}
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Paul D. Hanna, Oct 23 2005
STATUS
approved