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A072076
Largest k such that EulerPhi(k) = 10^n.
3
2, 22, 250, 3750, 41250, 414150, 4166250, 42281250, 438281250, 4400343750, 44266406250, 449238281250, 4510352343750, 45373066406250, 455545586718750, 4555455867187500, 45555287544813750, 455552875448137500, 4566844506855468750, 45668445068554687500
OFFSET
0,1
LINKS
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
KEYWORD
nonn
AUTHOR
Labos Elemer, Jun 13 2002
EXTENSIONS
More terms from Max Alekseyev, Apr 26 2010
STATUS
approved