A182909 - OEIS

%I #6 Mar 30 2012 18:57:12

%S 3,6,7,10,14,15,18,23,27,32,41,42,44,53,68,70,78,86,91,100,101,102,

%T 103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,

%U 120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142

%N Ranks of composite numbers when all prime powers p^n for n>=1 are jointly ranked.

%C The complement of A027883.

%e In the sequence A000961 (2,3,4,5,7,8,9,11,13,16,

%e 17,19,23,25,27,...) of prime powers p^n for n>=1, the

%e composites 4,8,9,16,25,27,... occur with ranks

%e 3,6,7,10,14,15...

%t T[i_,j_]:=Sum[Floor[j*Log[Prime[i]]/Log[Prime[h]]],{h,1,PrimePi[Prime[i]^j]}]; Complement[Range[200],Table[Flatten[Table[T[i,j],{i,1,80},{j,1,1}]]]

%Y Cf. A000961, A024620, A027883.

%K nonn

%O 1,1

%A _Clark Kimberling_, Dec 13 2010