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A298071 Number of primes between floor(3*n/2) and 2*n (inclusive). 1
1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 3, 2, 3, 3, 3, 4, 4, 3, 4, 3, 3, 3, 4, 3, 3, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 6, 5, 5, 4, 5, 4, 5, 6, 6, 6, 7, 6, 7, 7, 7, 6, 6, 6, 6, 7, 7, 7, 7, 6, 7, 7, 7, 6, 6, 5, 6, 6, 6, 6, 7, 7, 7, 8, 8, 9, 9, 8, 9, 8, 8, 9, 10, 9 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,7
LINKS
MATHEMATICA
a[n_] := PrimePi[2*n] - PrimePi[Floor[3*n/2]] + If[PrimeQ[Floor[ 3*n/2]], 1, 0]; Array[a, 100] (* Jean-François Alcover, Jan 11 2018 *)
PROG
(Sage)
A298071 = lambda n: len([p for p in (3*n//2..2*n) if is_prime(p)])
print([A298071(n) for n in (1..97)]) # Peter Luschny, Jan 11 2018
CROSSREFS
Sequence in context: A055027 A214574 A342510 * A246920 A244964 A096993
KEYWORD
nonn
AUTHOR
Bruno Berselli, Jan 11 2018
STATUS
approved

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Last modified May 20 11:46 EDT 2024. Contains 372712 sequences. (Running on oeis4.)