A264810 Number of numbers k <= n such that phi(m) = k for some m.

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

Offset: 1

Author

Reinhard Zumkeller, Nov 26 2015

Keywords

• nonn

Comments

Partial sums of A264739;

a(n) = n - A180639(n).

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000010, A002202, A264739.

Programs

Haskell

a264810 n = a264810_list !! (n-1)
a264810_list = scanl1 (+) a264739_list

PARI

first(n)=my(s); vector(n,k,s+=istotient(k)) \\ Charles R Greathouse IV, Sep 02 2015