Denominator of smallest nonnegative fraction of form +- 1 +- 1/2 +- 1/3 ... +- 1/n.

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =12a(5) =60a(6) =20a(7) =420a(8) =840a(9) =2520a(10) =2520a(11) =27720a(12) =27720a(13) =360360a(14) =360360a(15) =360360a(16) =144144a(17) =12252240a(18) =12252240a(19) =232792560a(20) =232792560a(21) =232792560a(22) =46558512a(23) =5354228880a(24) =5354228880a(25) =2974571600a(26) =26771144400a(27) =80313433200