A109497 - OEIS

A109497

Number of lucky numbers <= n.

1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 5, 5, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 13, 13, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 17, 17, 17, 17, 18, 18, 19, 19, 19, 19, 20, 20

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

OFFSET

0,3

REFERENCES

R. K. Guy, Unsolved Problems in Number Theory, C3.

LINKS

Table of n, a(n) for n=0..79.

V. Gardiner, R. Lazarus, N. Metropolis, and S. Ulam, On certain sequences of integers defined by sieves, Mathematics Magazine, 29(3) (1955), 117-122.

Martin Gardner, Lucky numbers and 2187, Math. Intellig., 19(2) (1997), 26-29.

I. Peterson, MathTrek, Martin Gardner's Lucky Numbers

Eric Weisstein's World of Mathematics, Lucky Number

Wikipedia, Lucky Number