

A182811


CyclopsLucas numbers.


2




OFFSET

1,1


COMMENTS

a(4) = 688846502588399 is the only known CyclopsLucas prime.
It seems likely that these four are the only terms. There are no further terms below Lucas(10^7), and that number in decimal contains 208435 zeros (with ~208988 expected assuming normality), whereas a member of this sequence must have only 1.  D. S. McNeil, Dec 21 2010
This sequence is similar to A182809 in the sense that both have four positive terms and the only known prime is also the largest known term.  Omar E. Pol, Dec 21 2010


LINKS



FORMULA



EXAMPLE

a(1) = 64079 is in the sequence because 64079 is a Lucas number and it is also a cyclops number.


MATHEMATICA

(* First run the program given for A134808 *) Select[LucasL[Range[10^3]], cyclopsQ] (* Alonso del Arte, Dec 20 2010 *)
Select[LucasL[Range[500]], OddQ[IntegerLength[#]]&&DigitCount[#, 10, 0]==1&&IntegerDigits[#][[(IntegerLength[#]+1)/2]]==0&] (* Harvey P. Dale, Jul 01 2017 *)


CROSSREFS



KEYWORD

nonn,base,hard,more


AUTHOR



STATUS

approved



