A155509 Larger of emirps (pairs) with digits 1 and 9 only.

991, 99119, 191911, 911111, 919111, 999199, 1911911, 1991911, 9111911, 11911111, 19911191, 19919111, 19991911, 99111119, 911111191, 991111111, 991991111, 999199991, 999919919, 1911119911, 1919991191, 1991111911, 1991919191

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Mathematica

le19[n_]:=Module[{emrps=Select[FromDigits/@Tuples[{1, 9}, n], !PalindromeQ[ #] && AllTrue[ {#, IntegerReverse[#]}, PrimeQ]&]}, If[IntegerReverse[#]>#, IntegerReverse[ #], {}]&/@emrps/.{}->Nothing]; Flatten[Table[le19[x], {x, 10}]] // Sort (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Apr 04 2019 *)

Crossrefs

A006567, A155507, A155508

Sequence in context: A031790 A137703 A255098 * A093177 A161926 A172698

Adjacent sequences: A155506 A155507 A155508 * A155510 A155511 A155512

Keyword

nonn,base

Author

Lekraj Beedassy, Jan 23 2009

Extensions

More terms from Sean A. Irvine, Apr 06 2010

Status

approved