A160561 Cyclops primes with circular digits {0,6,8,9}.

809, 66089, 68099, 86069, 88069, 89069, 99089, 6680689, 6680699, 6680969, 6690689, 6690899, 6690989, 6860869, 6860989, 6860999, 6890699, 6890969, 6960869, 6980669, 6980899, 6980969, 6990889, 8660689, 8660699, 8660969

Offset: 1

Author

Ki Punches, May 19 2009

Keywords

• nonn
• base

Comments

The sequence is probably infinite.

The sequence A134809 restricted to cases with digits 6, 8 or 9 (see A001743) at the off-center positions.

Primes in A274765. - Omar E. Pol, Jul 06 2016

Each term is equal to 9 mod 10. - Harvey P. Dale, Feb 02 2021

Links

• Kenny Lau, Table of n, a(n) for n = 1..20000

Crossrefs

Intersection of A000040 (primes), A001743 (numbers with circular digits) and A134808 (cyclops numbers).

Also intersection of A043580 (primes with circular digits) and A134809 (cyclops primes).

Cf. A134808, A134809, A153807, A156200, A274765.

Programs

Mathematica

Select[Prime@ Range[10^6], And[OddQ@ Length@ #, Times @@ Boole@ Map[MemberQ[{0, 6, 8, 9}, #] &, Union@ #] == 1, Part[#, Ceiling[Length[#]/2]] == 0, Count[#, 0] == 1] &@ IntegerDigits@ # &] (* Michael De Vlieger, Jul 05 2016 *)
Table[Select[FromDigits/@(Flatten[Join[{Take[#,Length[#]/2],0,Take[#,-Length[#]/2]}]]&/@Tuples[{6,8,9},n]),PrimeQ],{n,2,6,2}]//Flatten (* Harvey P. Dale, Feb 02 2021 *)

Extensions

Edited and corrected by Ray Chandler and R. J. Mathar, May 20 2009

Definition simplified by Omar E. Pol, Jun 05 2009