A178758 - OEIS

%I #4 Apr 04 2015 21:45:22

%S 1,2,6,8,18,21,33,38,54,66,83,89,106,124,150,166,190,208,232,250

%N Smallest range 1..a(n) that permits n integers x() in 1..a(n) to exist with (x(i)-x(j)) mod (x(k)-x(j)) nonzero whenever i,j,k are disjoint.

%C Maximal non-interfering picket-fence seeds: a picket fence extended from any pair in the set encounters no other member of the set

%e a(1) 1

%e a(2) 1 2

%e a(3) 1 3 6

%e a(4) 1 3 6 8

%e a(5) 1 4 8 14 18

%e a(6) 1 4 8 14 18 21

%e a(7) 1 4 8 14 23 30 33

%e a(8) 1 5 11 15 24 28 34 38

%e a(9) 1 10 16 20 23 27 33 42 54

%e a(10) 1 7 11 17 26 32 40 52 60 66

%e a(11) 1 7 15 21 30 36 46 58 68 74 83

%e a(12) 1 7 15 21 30 36 46 58 68 74 83 89

%e a(13) 1 9 15 24 30 40 52 67 77 83 92 98 106

%e a(14) 1 10 22 30 36 51 57 68 74 89 95 103 115 124

%e a(15) 1 7 22 28 36 48 56 69 81 98 107 113 122 138 150

%e a(16) 1 7 15 27 45 59 65 74 93 102 108 122 140 152 160 166

%e a(17) 1 13 29 35 44 51 63 81 92 110 122 129 138 144 160 172 190

%e a(18) 1 19 31 47 53 62 69 81 99 110 128 140 147 156 162 178 190 208

%e a(19) 1 13 24 33 45 63 75 84 100 115 131 140 152 170 182 191 202 214 232

%e a(20) 1 19 31 42 51 63 81 93 102 118 133 149 158 170 188 200 209 220 232 250

%e (lexicographically earliest solutions)

%K nonn

%O 1,2

%A _R. H. Hardin_ Jun 10 2010