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A060969
Number of prime cubes <= 2^n.
0
0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 6, 8, 9, 11, 12, 15, 18, 22, 26, 31, 37, 46, 54, 66, 79, 97, 117, 141, 172, 209, 257, 309, 376, 457, 564, 687, 842, 1028, 1266, 1549, 1900, 2327, 2861, 3512, 4323, 5320, 6542, 8072, 9936, 12251, 15104, 18640, 23000, 28428
OFFSET
0,6
FORMULA
a(3*n) = A007053(n). - Chai Wah Wu, Jan 23 2025
EXAMPLE
n=10, prime-cubes not exceeding 1024 are: 8,27,125,343 so a(10)=4.
MATHEMATICA
Table[ PrimePi[ Floor[ 2^(g/3)//N ] ], {g, 0, 90} ]
CROSSREFS
Sequence in context: A279766 A029027 A035448 * A367694 A358151 A152162
KEYWORD
nonn
AUTHOR
Labos Elemer, May 09 2001
EXTENSIONS
Missing a(0)=0 inserted by Sean A. Irvine, Jan 09 2023
STATUS
approved