a(1) = 1; for n>1, a(n) = a(n-1)*n if n is prime, a(n) = a(n-1)/n if n is composite dividing a(n-1) else a(n) = a(n-1).

A085087

a(1) = 1; for n>1, a(n) = a(n-1)*n if n is prime, a(n) = a(n-1)/n if n is composite dividing a(n-1) else a(n) = a(n-1).

Terms

    a(0) =1a(1) =2a(2) =6a(3) =6a(4) =30a(5) =5a(6) =35a(7) =35a(8) =35a(9) =35a(10) =385a(11) =385a(12) =5005a(13) =5005a(14) =5005a(15) =5005a(16) =85085a(17) =85085a(18) =1616615a(19) =1616615a(20) =1616615a(21) =1616615a(22) =37182145a(23) =37182145a(24) =37182145a(25) =37182145a(26) =37182145a(27) =37182145a(28) =1078282205a(29) =1078282205

External references