Denominator of the n-th alternating harmonic number, Sum_{k=1..n} (-1)^(k+1)/k.

Terms

a(0) =1a(1) =2a(2) =6a(3) =12a(4) =60a(5) =60a(6) =420a(7) =840a(8) =2520a(9) =2520a(10) =27720a(11) =27720a(12) =360360a(13) =360360a(14) =72072a(15) =144144a(16) =2450448a(17) =2450448a(18) =46558512a(19) =232792560a(20) =232792560a(21) =232792560a(22) =5354228880a(23) =5354228880a(24) =26771144400a(25) =26771144400a(26) =80313433200a(27) =11473347600