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Search: id:A145536
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| A145536 |
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a(n)=number of numbers removed in each step of Eratosthenes' sieve for 9! |
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+0
2
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| 181439, 60479, 24191, 13823, 7540, 5800, 4092, 3446, 2701, 2046, 1842, 1487, 1296, 1200, 1070, 927, 817, 782, 703, 665, 645, 600, 574, 538, 498, 477, 465, 451, 441, 425, 385, 372, 351, 346, 326, 322, 308, 294, 288, 277, 267, 263, 248, 246, 238, 236, 221
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Number of steps in Eratosthenes' sieve for n! is A133228(n).
Number of primes less than 9! is equal = 9!-(sum all numbers in this sequence)-1 = A003604(9).
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MATHEMATICA
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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 = 9; kk = PrimePi[Sqrt[nn! ]]; t3 = f3[nn!, kk] (*Bob Hanlon*)
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CROSSREFS
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A003604, A133228, A145532-A145540
Sequence in context: A056748 A060232 A133541 this_sequence A030466 A086478 A024754
Adjacent sequences: A145533 A145534 A145535 this_sequence A145537 A145538 A145539
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KEYWORD
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fini,nonn
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AUTHOR
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Artur Jasinski with assistence from Bob Hanlon (grafix(AT)csl.pl), Oct 14 2008
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