

A061091


Number of k with 1 <= k <= n relatively prime to phi(k).


2



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

1,2


COMMENTS

Limit_{n>oo} a(n) * log(log(log(n))) / n = 1/exp(gamma).


REFERENCES

Steven R. Finch, Mathematical Constants, Cambridge, 2003, pp. 115119.


LINKS



FORMULA

a(n) = Sum_{k=1..n} gcd(k, phi(k)) = 1.


PROG



CROSSREFS



KEYWORD

nonn,easy


AUTHOR



STATUS

approved



