%I
%S 8,24,28,34,50,52,58,71,77,163,197,235,238,319,570,669,949,958,1211,
%T 1305
%N Numbers n such that the nth Fibonacci number is composite and the concatenation of its prime factors (written in base 10 in ascending order) is prime.
%H Blair Kelly, <a href="http://mersennus.net/fibonacci/">Fibonacci and Lucas Factorizations</a>.
%e F(24) = 46368 = 2^5 * 3^2 * 7 * 23 is composite and the concatenation 2222233723 is prime, so 24 is in the sequence.
%Y Cf. A000045, A037276, A038526.
%K nonn,base,hard,more
%O 1,1
%A _Jeff Burch_
%E More terms from _Jens Kruse Andersen_, Jan 05 2003
%E a(17)a(18) from _Ryan Propper_, May 29 2006
%E a(19)a(20) from _Sean A. Irvine_, Jan 16 2021
