Least k such that Sum_{i=1..n} k^n / i is a positive integer.

Terms

a(0) =1a(1) =2a(2) =6a(3) =6a(4) =30a(5) =10a(6) =70a(7) =70a(8) =210a(9) =210a(10) =2310a(11) =2310a(12) =30030a(13) =30030a(14) =30030a(15) =30030a(16) =510510a(17) =510510a(18) =9699690a(19) =1939938a(20) =646646a(21) =646646a(22) =14872858a(23) =44618574a(24) =223092870a(25) =223092870a(26) =223092870a(27) =223092870a(28) =6469693230a(29) =6469693230