OFFSET
1,1
COMMENTS
Is this sequence infinite?
EXAMPLE
Prime number 7391381 is a term because sigma(sigma(7391381)) = 14930352 is a Fibonacci number.
PROG
(PARI) isFibonacci(n)=my(k=n^2); issquare(k+=(k+1)<<2) || (n>0 && issquare(k-8));
is(n)=isFibonacci(sigma(n+1))&&isprime(n);
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Jan 05 2017
EXTENSIONS
Terms confirmed by Giovanni Resta, Jan 07 2017
STATUS
approved