A155507 -id:A155507 - cp's OEIS frontend

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

Lekraj Beedassy, Jan 23 2009

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

A006567, A155507, A155509

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 *)

More terms from Sean A. Irvine, Apr 06 2010

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

Original entry on oeis.org

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

Lekraj Beedassy, Jan 23 2009

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

A006567, A155507, A155508

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 *)

More terms from Sean A. Irvine, Apr 06 2010

cp's OEIS Frontend

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

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