A079633 a(n) = floor(n/floor(n^(1/3))) - floor(n^(2/3)).
0, 1, 1, 2, 3, 3, 4, 0, 0, 1, 1, 1, 1, 2, 1, 2, 2, 3, 2, 3, 3, 4, 3, 4, 4, 5, 0, 0, 0, 1, 1, 0, 1, 1, 1, 2, 1, 1, 2, 2, 2, 2, 2, 2, 3, 3, 2, 3, 3, 3, 4, 4, 3, 4, 4, 4, 5, 5, 4, 5, 5, 5, 6, 0, 0, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 2, 1, 1, 1, 2, 2, 2, 1, 2, 2, 2, 2, 3, 3, 2, 2, 3, 3, 3, 3, 4, 3, 3, 3, 4, 4, 4, 4, 4, 4
Offset: 1
Keywords
Programs
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PARI
a(n)=floor(n/sqrtnint(n,3))-sqrtnint(n^2,3)
Formula
For n > 4: Max_{k=1..n} a(k) = ceiling((n+2)^(1/3)) + 1.