Floor of area of triangle whose sides are consecutive Ulam numbers (A002858).

Terms

a(0) =0a(1) =2a(2) =5a(3) =11a(4) =23a(5) =43a(6) =70a(7) =100a(8) =141a(9) =227a(10) =361a(11) =478a(12) =670a(13) =826a(14) =1044a(15) =1183a(16) =1405a(17) =1668a(18) =1960a(19) =2272a(20) =2545a(21) =2889a(22) =3351a(23) =3819a(24) =4267a(25) =4523a(26) =4955a(27) =5669a(28) =6558a(29) =7474