Greatest common divisor of n! and its arithmetic derivative.

Terms

a(0) =1a(1) =1a(2) =1a(3) =4a(4) =4a(5) =48a(6) =48a(7) =192a(8) =1728a(9) =34560a(10) =34560a(11) =414720a(12) =414720a(13) =2903040a(14) =130636800a(15) =2090188800a(16) =2090188800a(17) =25082265600a(18) =25082265600a(19) =501645312000