a(n) = floor(3rd elementary symmetric function of Sum_{j=1..k} 1/j, k = 1,2,...,n).

Terms

a(0) =2a(1) =15a(2) =49a(3) =122a(4) =255a(5) =472a(6) =804a(7) =1284a(8) =1950a(9) =2842a(10) =4005a(11) =5488a(12) =7341a(13) =9619a(14) =12380a(15) =15683a(16) =19594a(17) =24177a(18) =29503a(19) =35642a(20) =42669a(21) =50662a(22) =59699a(23) =69863a(24) =81238a(25) =93910a(26) =107969a(27) =123505a(28) =140612a(29) =159386