OFFSET
0,2
EXAMPLE
Triangle Q^-1 begins:
1;
-2,1;
4,-5,1;
21,-5,-8,1;
130,20,-32,-11,1;
1106,840,-260,-77,-14,1;
10044,24865,-2584,-1089,-140,-17,1;
-18366,823383,-12828,-21428,-2737,-221,-20,1; ...
Triangle Q^-2 begins:
1;
-4,1;
18,-10,1;
20,30,-16,1;
-139,255,24,-22,1;
-3945,3085,544,0,-28,1;
-99849,51015,12444,671,-42,-34,1; ...
PROG
(PARI) T(n, k)=local(P, Q, R, W); P=Mat(1); for(m=2, n+1, W=matrix(m, m); for(i=1, m, for(j=1, i, if(i<3 || j==i || j>m-1, W[i, j]=1, if(j==1, W[i, 1]=1, W[i, j]=(P^(3*j-2))[i-j+1, 1])); )); P=W); Q=matrix(#P, #P, r, c, if(r>=c, (P^(3*c-1))[r-c+1, 1])); (Q^-1)[n+1, k+1]
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Paul D. Hanna, Nov 15 2005
STATUS
approved