A139179 - OEIS

A139179

Number of non-fourth-powers <= n.

0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70

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OFFSET

0,4

LINKS

Table of n, a(n) for n=0..72.

FORMULA

a(n) = n - floor(n^(1/4)).

MATHEMATICA

a[n_] := n - Floor[n^(1/4)]; a /@ Range[0, 72] (* Giovanni Resta, Jun 21 2016 *)

PROG

(Python)

from sympy import integer_nthroot