Number of distinct products i*j*k*l*m for 1 <= i <= j <= k <= l <= m <= n.

Terms

a(0) =1a(1) =6a(2) =21a(3) =36a(4) =91a(5) =126a(6) =266a(7) =336a(8) =441a(9) =546a(10) =994a(11) =1120a(12) =1890a(13) =2184a(14) =2562a(15) =2856a(16) =4482a(17) =4932a(18) =7392a(19) =8052a(20) =9042a(21) =10032a(22) =14377a(23) =15092a(24) =17237a(25) =18887a(26) =20812a(27) =22297a(28) =30635a(29) =31856