A072076 Largest k such that EulerPhi(k) = 10^n.

2, 22, 250, 3750, 41250, 414150, 4166250, 42281250, 438281250, 4400343750, 44266406250, 449238281250, 4510352343750, 45373066406250, 455545586718750, 4555455867187500, 45555287544813750, 455552875448137500, 4566844506855468750, 45668445068554687500

Offset

0,1

Links

Ray Chandler, Table of n, a(n) for n = 0..1000

Max A. Alekseyev, Computing the Inverses, their Power Sums, and Extrema for Euler's Totient and Other Multiplicative Functions. Journal of Integer Sequences, Vol. 19 (2016), Article 16.5.2

Formula

a(n) = Max{k; A000010(k) = 10^n}.

Example

n=3: a(3)=3750 because InvPhi(1000) = {1111, 1255, 1375, 1875, 2008, 2222, 2500, 2510, 2750, 3012, 3750}.

Crossrefs

Cf. A000010, A014197, A014573, A072074, A072075, A110076.

Sequence in context: A342232 A082777 A229465 * A226706 A036841 A307852

Adjacent sequences: A072073 A072074 A072075 * A072077 A072078 A072079

Keyword

nonn

Author

Labos Elemer, Jun 13 2002

Extensions

More terms from Max Alekseyev, Apr 26 2010

Status

approved