OFFSET
1,1
COMMENTS
Primes in A066812.
LINKS
Giovanni Resta, Table of n, a(n) for n = 1..675
FORMULA
a(n) = prime(A066902(n)). - Giovanni Resta, Apr 06 2020
MATHEMATICA
Select[Prime[Range[124*10^4]], EulerPhi[#-1]==EulerPhi[#+1]&] (* Harvey P. Dale, Apr 09 2019 *)
PROG
(PARI) v=[]; forprime(p=2, 40000000, if(eulerphi(p+1)==eulerphi(p-1), v=concat(v, p))); v
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Mar 02 2002
EXTENSIONS
More terms from Rick L. Shepherd, May 03 2002
STATUS
approved