OFFSET
0,1
COMMENTS
Carmichael conjectured that no term exists for n=1.
REFERENCES
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 840.
LINKS
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
Max Alekseyev, PARI/GP Scripts for Miscellaneous Math Problems (invphi.gp).
Eric Weisstein's World of Mathematics, Carmichael's Totient Function conjecture
PROG
(PARI) a(n) = if (n==1, 0, my(k=1); while (#invphi(k) != n, k++); k); \\ using invphi in PARI scripts link; Michel Marcus, Oct 09 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
EXTENSIONS
Link fixed by Charles R Greathouse IV, Oct 06 2009
STATUS
approved