a(n-1)+k=a(n) => a(n)*k=a(n+1).A057268a(n-1)+k=a(n) => a(n)*k=a(n+1).Terms a(0) =1a(1) =3a(2) =6a(3) =18a(4) =216a(5) =42768a(6) =1819863936External referencesoeis: A057268