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
Links
- Harvey P. Dale, Table of n, a(n) for n = 1..1000
Programs
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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 *)
Extensions
More terms from Sean A. Irvine, Apr 06 2010