OEIS/Cheat sheet

PARI

for(n=0,10,for(k=0,n,print1(",",T(n,k)));print()) \\ Print triangle T(n,k)

Maple

ode:=algtorec(x^2*(1+x^2)*A^2-(1+x^2+x^4)*A+1+x^2,A,x,n,N);
OperToRecEq(ode,n,N,a);