a(n) = numerator( [(x*y*z*u)^n] 1/sqrt(1 - (x + y + z + u*(y + z))) ).

A381267

a(n) = numerator( [(x*y*z*u)^n] 1/sqrt(1 - (x + y + z + u*(y + z))) ).

Terms

    a(0) =1a(1) =15a(2) =31185a(3) =6381375a(4) =409933148625

External references