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

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =8a(8) =9a(9) =10a(10) =11a(11) =12a(12) =13a(13) =15a(14) =16a(15) =17a(16) =18a(17) =19a(18) =20a(19) =22a(20) =23a(21) =24a(22) =25a(23) =27a(24) =28a(25) =31a(26) =32a(27) =33a(28) =34a(29) =36