a(n) = least positive integer > a(n-1) and not (a(i)+a(j))^2 - a(k)^2 for 1<=i<=j<=k<=n.

Terms

a(0) =1a(1) =3a(2) =4a(3) =5a(4) =6a(5) =8a(6) =10a(7) =12a(8) =14a(9) =15a(10) =16a(11) =18a(12) =19a(13) =22a(14) =23a(15) =26a(16) =30a(17) =32a(18) =34a(19) =35a(20) =38a(21) =40a(22) =41a(23) =42a(24) =43a(25) =46a(26) =49a(27) =50a(28) =51a(29) =54