Values of usigma(n) = usigma(n+1).

Terms

a(0) =24a(1) =60a(2) =72a(3) =180a(4) =1440a(5) =2160a(6) =1872a(7) =2640a(8) =2400a(9) =3000a(10) =2880a(11) =3024a(12) =4320a(13) =4320a(14) =4320a(15) =5280a(16) =5280a(17) =7400a(18) =8640a(19) =10080a(20) =10200a(21) =11520a(22) =11880a(23) =11520a(24) =11088a(25) =12960a(26) =12096a(27) =14400a(28) =25920a(29) =21600