Minimal scope of an (n,3) difference triangle.

Terms

a(0) =6a(1) =13a(2) =19a(3) =24a(4) =30a(5) =36a(6) =42a(7) =48a(8) =54a(9) =60a(10) =66a(11) =72a(12) =78a(13) =84a(14) =90a(15) =96a(16) =102a(17) =108a(18) =114a(19) =120a(20) =126a(21) =132a(22) =138a(23) =144a(24) =150a(25) =156a(26) =162a(27) =168