OFFSET
1,1
COMMENTS
The sequence appears to be infinite, but I have no proof.
There are many consecutive elements in the sequence: (13,14)-(36,37)-...-(12777,12778)-...(30236,30237)-...
EXAMPLE
a(10)=37 since 5+phi(37)^2=1301 is a prime.
MATHEMATICA
Select[Range[250], PrimeQ[EulerPhi[#]^2+5]&] (* Harvey P. Dale, Jun 07 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Carmine Suriano, Sep 14 2010
STATUS
approved