OFFSET
0,2
EXAMPLE
Triangle R^-1 begins:
1;
-3,1;
3,-6,1;
35,-12,-9,1;
396,-29,-45,-12,1;
6237,582,-462,-96,-15,1;
131613,30684,-6408,-1534,-165,-18,1;
3518993,1300810,-96705,-34020,-3515,-252,-21,1; ...
Triangle R^-2 begins:
1;
-6,1;
24,-12,1;
79,30,-18,1;
324,356,18,-24,1;
42,5523,615,-12,-30,1;
-79346,112533,16731,640,-60,-36,1; ...
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); R=matrix(#P, #P, r, c, if(r>=c, (P^(3*c))[r-c+1, 1])); (R^-1)[n+1, k+1]
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Paul D. Hanna, Nov 15 2005
STATUS
approved