Integer part of ((2nd elementary symmetric function of 1,2,...,n)/(1+2+...+n)).

Terms

a(0) =0a(1) =0a(2) =1a(3) =3a(4) =5a(5) =8a(6) =11a(7) =15a(8) =19a(9) =24a(10) =29a(11) =34a(12) =41a(13) =47a(14) =54a(15) =62a(16) =70a(17) =79a(18) =88a(19) =98a(20) =108a(21) =119a(22) =130a(23) =141a(24) =154a(25) =166a(26) =179a(27) =193a(28) =207a(29) =222