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

Terms

a(0) =1a(1) =2a(2) =6a(3) =6a(4) =30a(5) =20a(6) =140a(7) =140a(8) =210a(9) =42a(10) =462a(11) =462a(12) =12012a(13) =3432a(14) =6006a(15) =6006a(16) =87516a(17) =87516a(18) =1108536a(19) =3048474a(20) =2586584a(21) =2586584a(22) =44618574a(23) =44618574a(24) =60843510a(25) =17160990a(26) =17160990a(27) =14263680a(28) =782050830a(29) =782050830