[ 3rd elementary symmetric function of {sqrt(k+1)} ], k = 1,2,...,n.

Terms

a(0) =4a(1) =24a(2) =74a(3) =175a(4) =357a(5) =656a(6) =1116a(7) =1791a(8) =2742a(9) =4042a(10) =5772a(11) =8024a(12) =10902a(13) =14519a(14) =19002a(15) =24487a(16) =31125a(17) =39079a(18) =48524a(19) =59649a(20) =72657a(21) =87763a(22) =105199a(23) =125209a(24) =148054a(25) =174008a(26) =203362a(27) =236422a(28) =273509a(29) =314962