OFFSET
1,2
LINKS
Donovan Johnson, Table of n, a(n) for n = 1..300
MATHEMATICA
uphi[n_] := Times@@(Power@@#-1&/@FactorInteger[n]); For[y=1, True, y++, If[uphi[x=y+(u=uphi[y])]==u, Print[{y, x}]]]
CROSSREFS
KEYWORD
nonn
AUTHOR
EXTENSIONS
Edited by Dean Hickerson, Mar 07 2002
Offset corrected by Donovan Johnson, May 04 2013
STATUS
approved