A155508 Lesser of emirps (pairs) with digits 1 and 9 only.

199, 91199, 111119, 111919, 119191, 991999, 1191119, 1191191, 1191991, 11111911, 11191991, 11919991, 19111991, 91111199, 111111199, 111199199, 191111119, 199991999, 919919999, 1111111999, 1191111991, 1199111191, 1911199999

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..660

Mathematica

Flatten[Table[Select[Subsets[Select[FromDigits/@Tuples[{1, 9}, n], PrimeQ], {2}], AllTrue[#, PrimeQ]&&#[[1]]==IntegerReverse[#[[2]]]&][[All, 1]], {n, 3, 10}]/.{}->Nothing] (* Harvey P. Dale, Aug 21 2020 *)

Crossrefs

A006567, A155507, A155509

Sequence in context: A097732 A305413 A181007 * A028482 A111472 A033523

Adjacent sequences: A155505 A155506 A155507 * A155509 A155510 A155511

Keyword

nonn,base

Author

Lekraj Beedassy, Jan 23 2009

Extensions

More terms from Sean A. Irvine, Apr 06 2010

Status

approved