OFFSET
0,5
COMMENTS
Complementary to A114150, which gives R^2*Q^-1 = Q^3*P^-2.
EXAMPLE
Triangle R^-2*Q^3 = Q^-1*P^2 begins:
1;
0,1;
0,3,1;
0,15,6,1;
0,136,66,9,1;
0,1998,1091,153,12,1;
0,41973,24891,3621,276,15,1; ...
Compare to R (A113389):
1;
3,1;
15,6,1;
136,66,9,1;
1998,1091,153,12,1;
41973,24891,3621,276,15,1; ...
Thus R^-2*Q^3 = Q^-1*P^2 equals R shift right one column.
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])); R=matrix(#P, #P, r, c, if(r>=c, (P^(3*c))[r-c+1, 1])); (Q^-1*P^2)[n+1, k+1]
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul D. Hanna, Nov 15 2005
STATUS
approved