A179038 Emirps whose only prime digits are 7's.

17, 71, 79, 97, 107, 167, 179, 701, 709, 761, 769, 907, 967, 971, 1097, 1471, 1487, 1741, 1789, 1847, 1867, 1879, 1979, 7177, 7187, 7481, 7649, 7681, 7687, 7699, 7717, 7817, 7841, 7867, 7879, 7901, 7949, 9467, 9479, 9497, 9679, 9749, 9769, 9781, 9787

Offset

1,1

Links

Table of n, a(n) for n=1..45.

Mathematica

okQ[n_]:=Module[{idn=IntegerDigits[n], rev}, rev=Reverse[idn]; idn!=rev && Union[Select[idn, PrimeQ]]=={7}&&PrimeQ[FromDigits[rev]]]; Select[ Prime[ Range[1300]], okQ] (* Harvey P. Dale, Jul 18 2011 *)

Crossrefs

Cf. A006567, A179039.

Sequence in context: A327495 A183943 A180532 * A179039 A152295 A039407

Adjacent sequences: A179035 A179036 A179037 * A179039 A179040 A179041

Keyword

base,nonn

Author

Lekraj Beedassy, Jun 25 2010

Extensions

Terms confirmed by Ray Chandler, Jul 13 2010

Status

approved