%I #4 Mar 30 2012 18:56:55

%S 1,4,5,7,12,21,31,43,56,71,89,110,133,162,194,228,265,306,349,394,441,

%T 489,542,598,655,715,778,843,912,984,1058,1133,1209,1289,1370,1453,

%U 1539,1626,1719,1813,1909,2006,2105,2205,2309,2416

%N a(n)=least number m such that m-a(n-1)<>a(j)-a(k) for all j,k less than m; a(1)=1, a(2)=4.

%K nonn

%O 1,2

%A _Clark Kimberling_