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A145590 a(n)=number of numbers removed in each step of Eratosthenes' sieve for 2^12. 0
2047, 682, 272, 155, 83, 65, 46, 40, 32, 25, 22, 18, 13, 11, 9, 6, 3, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Number of steps in Eratosthenes' sieve for 2^n is A060967(n).

Number of primes less than 2^12 is equal = 2^12 - (sum all of numbers in this sequence) - 1 = A007053(12).

LINKS

Table of n, a(n) for n=1..18.

MATHEMATICA

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 (hanlonr(AT)cox.net) *)

CROSSREFS

A006880, A122121, A145532-A145540, A145583-A145592

Sequence in context: A068264 A024021 A298756 * A241039 A278353 A038462

Adjacent sequences:  A145587 A145588 A145589 * A145591 A145592 A145593

KEYWORD

fini,nonn

AUTHOR

Artur Jasinski with assistance from Bob Hanlon (hanlonr(AT)cox.net), Oct 14 2008

STATUS

approved

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Last modified February 16 21:37 EST 2020. Contains 331975 sequences. (Running on oeis4.)