login
Number of prime cubes <= 2^n.
0

%I #12 Jan 09 2023 21:29:52

%S 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,

%T 117,141,172,209,257,309,376,457,564,687,842,1028,1266,1549,1900,2327,

%U 2861,3512,4323,5320,6542,8072,9936,12251,15104,18640,23000,28428

%N Number of prime cubes <= 2^n.

%H <a href="/index/Pri#primepop">Index entries for sequences related to numbers of primes in various ranges</a>

%e n=10, prime-cubes not exceeding 1024 are: 8,27,125,343 so a(10)=4.

%t Table[ PrimePi[ Floor[ 2^(g/3)//N ] ], {g, 0, 90} ]

%Y Cf. A007053, A036386.

%K nonn

%O 0,6

%A _Labos Elemer_, May 09 2001

%E Missing a(0)=0 inserted by _Sean A. Irvine_, Jan 09 2023