%I #2 Mar 31 2012 13:21:19

%S 2,4,5,8,9,10,14,15,16,17,22,23,24,25,26,32,33,34,35,36,37,44,45,46,

%T 47,48,49,50,58,59,60,61,62,63,64,65,74,75,76,77,78,79,80,81,82,92,93,

%U 94,95,96,97,98,99,100,101,112,113,114,115,116,117,118,119,120,121

%N a(n) = 2*A000124(A003056(n-1)) if A002262(n-1)=0, otherwise a(n-1)+1.

%o (MIT Scheme:) (define (A166021 n) (if (zero? (A002262 (-1+ n))) (* 2 (A000124 (A003056 (-1+ n)))) (1+ (A166021 (-1+ n)))))

%Y Complement of A136272.

%K nonn,tabl,easy

%O 1,1

%A _Antti Karttunen_, Oct 05 2009