A026266 - OEIS

%I #4 Mar 30 2012 18:56:05

%S 1,2,3,4,5,6,10,7,11,12,8,13,9,19,20,21,14,22,23,15,16,17,18,29,30,31,

%T 32,24,38,25,39,26,40,41,27,42,28,48,49,50,33,51,34,35,36,37,57,58,59,

%U 60,61,43,67,44,68,45,69,70,46,47,76,77,78

%N a(n) = (1/2)*s(n), where s = A026262.

%K nonn

%O 1,2

%A _Clark Kimberling_