“…. , n k ] that minimises n k 2 [11] 3 [11,17] 4 [11,17,28] 5 [11,17,31,41] 6 [11,17,28,46,58] 7 [11,17,28,42,64,78] 8 [11,17,28,42,63,90, 107] 9 [11,17,28,46,58,91,122,140] 10 [11,17,28,42,64,78,122,157,177] 11 [11,17,28,42,63,90,107,165,204,226] 12 [11,17,…”