Denominator of n * n-th harmonic number.

Terms

a(0) =1a(1) =1a(2) =2a(3) =3a(4) =12a(5) =10a(6) =20a(7) =35a(8) =280a(9) =252a(10) =2520a(11) =2310a(12) =27720a(13) =25740a(14) =24024a(15) =45045a(16) =720720a(17) =680680a(18) =4084080a(19) =3879876a(20) =739024a(21) =235144a(22) =5173168a(23) =14872858a(24) =356948592a(25) =343219800a(26) =2974571600a(27) =2868336900a(28) =80313433200a(29) =77636318760