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A145532 Number of numbers removed in each step of Eratosthenes's sieve for 5!. 24

%I #14 Jan 03 2022 02:07:59

%S 59,19,7,4

%N Number of numbers removed in each step of Eratosthenes's sieve for 5!.

%C The number of steps in Eratosthenes's sieve for n! is A133228(n).

%C The number of primes less than 5! is 120 - 59 - 19 - 7 - 4 - 1 = 30 = A003604(5).

%e a(1)=59 because in first step we removed all numbers divisible by 2 (=60) with the exception of the first one, i.e., 2.

%e a(2)=19 because the number of numbers divisible by 3 and not divisible by 2 is 20 and we remove all with the exception of the first one, i.e., 3.

%Y Cf. A003604, A133228, A145532-A145540.

%K fini,nonn,full

%O 1,1

%A _Artur Jasinski_, Oct 12 2008

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Last modified March 18 22:56 EDT 2024. Contains 370952 sequences. (Running on oeis4.)