A079631 - OEIS

A079631

Number of k less than or equal to n such that floor(k^(1/3)) divides k.

1, 2, 3, 4, 5, 6, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 18, 18, 18, 19, 19, 19, 20, 20, 20, 21, 21, 21, 22, 22, 22, 23, 23, 23, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 28, 28, 29, 29, 29, 30, 31, 31, 31, 31, 32, 32, 32, 32, 33, 33

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

Concrete Mathematics Casino Problem - number of winners up to N.

REFERENCES

R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics. 2nd Edition. Addison-Wesley, Reading, MA, 1994. Section 3.2, p74-76.

LINKS

Hugo Pfoertner, Table of n, a(n) for n = 1..10000

FORMULA

a(n)=floor(n/floor(n^(1/3)))+1/2*floor(n^(1/3))^2+5/2*floor(n^(1/3))-3

EXAMPLE