%I #5 Mar 30 2012 18:56:45

%S 17,81,143,145,209,273,337,401,465,529,593,655,657,721,785,849,913,

%T 977,1041,1151,1167,1169,1233,1297,1361,1425,1489,1553,1617,1679,1681,

%U 1745,1809,1873,1937,2001,2065,2129,2191,2193,2257

%N Numbers n such that string 2,1 occurs in the base 8 representation of n but not of n+1.

%K nonn,base

%O 1,1

%A _Clark Kimberling_