This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A114159 #9 Jan 21 2025 06:31:10 %S A114159 1,-3,1,3,-6,1,35,-12,-9,1,396,-29,-45,-12,1,6237,582,-462,-96,-15,1, %T A114159 131613,30684,-6408,-1534,-165,-18,1,3518993,1300810,-96705,-34020, %U A114159 -3515,-252,-21,1,114244366,59124226,-764835,-944334,-102180,-6675,-357,-24,1 %N A114159 Triangle, read by rows, equal to the matrix inverse of R=A113389. %e A114159 Triangle R^-1 begins: %e A114159 1; %e A114159 -3,1; %e A114159 3,-6,1; %e A114159 35,-12,-9,1; %e A114159 396,-29,-45,-12,1; %e A114159 6237,582,-462,-96,-15,1; %e A114159 131613,30684,-6408,-1534,-165,-18,1; %e A114159 3518993,1300810,-96705,-34020,-3515,-252,-21,1; %e A114159 ... %e A114159 Triangle R^-2 begins: %e A114159 1; %e A114159 -6,1; %e A114159 24,-12,1; %e A114159 79,30,-18,1; %e A114159 324,356,18,-24,1; %e A114159 42,5523,615,-12,-30,1; %e A114159 -79346,112533,16731,640,-60,-36,1; %e A114159 ... %o A114159 (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]} %Y A114159 Cf. A113370 (P), A113381 (Q), A113389 (R); A114150 (R^2*Q^-1=Q^3*P^-2), A114151 (R^-2*Q^3=Q^-1*P^2), A114152 (R^3*P^-1), A114153 (R^-1*P^3), A114154 (R^3*Q^-2), A114155 (Q^-2*P^3); A114156 (P^-1), A114158 (Q^-1). %K A114159 sign,tabl %O A114159 0,2 %A A114159 _Paul D. Hanna_, Nov 15 2005