

A117491


The number of primes between n and n^3 (with n and n^3 excluded).


1



0, 3, 7, 16, 27, 44, 64, 93, 125, 164, 212, 264, 321, 394, 470, 558, 649, 758, 874, 999, 1139, 1290, 1448, 1624, 1812, 2011, 2218, 2451, 2697, 2951, 3217, 3501, 3806, 4126, 4472, 4810, 5182, 5567, 5983, 6401, 6837, 7295, 7775, 8279, 8796, 9347, 9901, 10484
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..48.


EXAMPLE

n=3 between 3+1 = 4 and 3^31 = 26 there are the following primes: 5, 7, 11, 13, 17, 19, 23. Therefore the number of primes is 7.


MAPLE

P:=proc(n) local i, j, np; for i from 1 by 1 to n do np:=0; for j from i+1 by 1 to i^31 do if isprime(j) then np:=np+1; fi; od; print(np); od; end: P(100);


MATHEMATICA

Table[PrimePi[n^3]PrimePi[n], {n, 50}] (* Harvey P. Dale, Nov 08 2012 *)


CROSSREFS

Cf. A060715, A117490.
Sequence in context: A221025 A036666 A218359 * A211379 A213180 A110585
Adjacent sequences: A117488 A117489 A117490 * A117492 A117493 A117494


KEYWORD

easy,nonn


AUTHOR

Paolo P. Lava and Giorgio Balzarotti, Mar 22 2006


STATUS

approved



