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A336304
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a(n) is the least number k such that the average number of prime divisors of {1..k} counted with multiplicity is >= n.
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3
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OFFSET
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0,2
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LINKS
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Table of n, a(n) for n=0..4.
Eric Weisstein's World of Mathematics, Prime Factor.
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EXAMPLE
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a(1) = 4 since the average number of prime divisors of {1..4} counted with multiplicity equals (0 + 1 + 1 + 2)/4 = 1 which is >= 1 and this is the least such number.
a(3) = 2178 because the average number of prime divisors of {1..2178} counted with multiplicity is >= 3 and this is the least such number.
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MATHEMATICA
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s[n_] := Module[{m = 0, c = 0, k = 1, sum = 0, seq = {}}, While[c < n, sum += PrimeOmega[k]; If[sum >= m*k, c++; AppendTo[seq, k]; m++]; k++]; seq]; s[4] (* Amiram Eldar, Nov 18 2020 *)
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PROG
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(PARI) a(n)=my(m=0, k=1); while(k>0, m+=bigomega(k); if(m>=k*n, break); k++); k \\ Derek Orr, Nov 18 2020
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CROSSREFS
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Cf. A001222, A022559, A085829, A328331, A338891, A338943.
Sequence in context: A257583 A258122 A012092 * A027639 A117620 A347484
Adjacent sequences: A336301 A336302 A336303 * A336305 A336306 A336307
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KEYWORD
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nonn,more
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AUTHOR
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Ilya Gutkovskiy, Nov 18 2020
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STATUS
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approved
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