%I A145590
%S A145590 2047,682,272,155,83,65,46,40,32,25,22,18,13,11,9,6,3,2
%N A145590 a(n)=number of numbers removed in each step of Eratosthenes' sieve for 
               2^12
%C A145590 Number of steps in Eratosthenes' sieve for 2^n is A060967(n).
%C A145590 Number of primes less than 2^12 is equal = 2^12 - (sum all of numbers 
               in this sequence) - 1 = A007053(12).
%t A145590 f3[k_Integer?Positive, i_Integer?Positive] := Module[{f, m, r, p}, p 
               = Transpose[{r = Range[2, i], Prime[r]}];f[x_] := Catch[Fold[If[Mod[x, 
               #2[[2]]] == 0, Throw[m[ #2[[1]]] = m[ #2[[1]]] + 1], #1] &, If[Mod[x, 
               2] == 0, Throw[m[1] = m[1] + 1]], p]]; Table[m[n] = -1, {n, i}]; 
               f /@ Range[k]; Table[m[n], {n, i}]];nn = 12; kk = PrimePi[Sqrt[2^nn]]; 
               t3 = f3[2^nn, kk] (*Bob Hanlon*)
%Y A145590 A006880, A122121, A145532-A145540, A145583-A145592
%Y A145590 Sequence in context: A115553 A068264 A024021 this_sequence A038462 A001262 
               A141232
%Y A145590 Adjacent sequences: A145587 A145588 A145589 this_sequence A145591 A145592 
               A145593
%K A145590 fini,nonn
%O A145590 1,1
%A A145590 Artur Jasinski with assistence from Bob Hanlon (grafix(AT)csl.pl), Oct 
               14 2008