a(n) = least positive integer > a(n-1) and not a(j)*a(k) + a(k)*a(i) + a(i)*a(j) for 1<=i<=j<=k<=n.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =10a(6) =17a(7) =18a(8) =22a(9) =23a(10) =25a(11) =29a(12) =30a(13) =31a(14) =38a(15) =39a(16) =41a(17) =42a(18) =46a(19) =49a(20) =50a(21) =52a(22) =55a(23) =57a(24) =58a(25) =62a(26) =65a(27) =66a(28) =67a(29) =70