213073domain: NAppears in sequencesT(n,0) + T(n,1) + ... + T(n,[ n/2 ]), T given by A027144.at n=15A027152Take pairs (x,y) with Sum_{j = x..y} j = concatenation of x and y. Sort pairs on y then x. This sequence gives y of each pair.at n=35A070153