a(n) = Product_{k=1..n} d(k); d(k) = A000005(k) is the number of positive divisors of k.

A066843

a(n) = Product_{k=1..n} d(k); d(k) = A000005(k) is the number of positive divisors of k.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =4a(4) =12a(5) =24a(6) =96a(7) =192a(8) =768a(9) =2304a(10) =9216a(11) =18432a(12) =110592a(13) =221184a(14) =884736a(15) =3538944a(16) =17694720a(17) =35389440a(18) =212336640a(19) =424673280a(20) =2548039680a(21) =10192158720a(22) =40768634880a(23) =81537269760a(24) =652298158080

External references