a(1) = 1; thereafter a(n) = a(n-1) / lpf(n) if lpf(n) divides a(n-1), otherwise a(n) = a(n-1) * lpf(n), where lpf is the least prime factor function A020639.
A337643
a(1) = 1; thereafter a(n) = a(n-1) / lpf(n) if lpf(n) divides a(n-1), otherwise a(n) = a(n-1) * lpf(n), where lpf is the least prime factor function A020639.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =3a(5) =15a(6) =30a(7) =210a(8) =105a(9) =35a(10) =70a(11) =770a(12) =385a(13) =5005a(14) =10010a(15) =30030a(16) =15015a(17) =255255a(18) =510510a(19) =9699690a(20) =4849845a(21) =1616615a(22) =3233230a(23) =74364290a(24) =37182145a(25) =7436429a(26) =14872858a(27) =44618574a(28) =22309287a(29) =646969323
External references
- oeis: A337643