OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
FORMULA
A050530(a(n)) = prime(n) and a(n) is the least number with this property.
EXAMPLE
The 31st term is 255 since 255 - phi(255) = 127, the 31st prime, and no number less than 255 has this property.
MATHEMATICA
With[{c=Table[n-EulerPhi[n], {n, 4000}]}, Table[Position[c, p, 1, 1], {p, Prime[ Range[ 60]]}]]//Flatten (* Harvey P. Dale, Sep 14 2020 *)
PROG
(PARI) a(n) = {my(k = 1); while(k - eulerphi(k) != prime(n), k++); k; } \\ Michel Marcus, Feb 02 2015
CROSSREFS
KEYWORD
nonn
AUTHOR
Labos Elemer, Jan 05 2000
STATUS
approved