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Palprimes of the form m*reversal(m)+1, sorted on m.
2

%I #7 Sep 10 2018 04:19:53

%S 2,5,11,101,1008001,1008001

%N Palprimes of the form m*reversal(m)+1, sorted on m.

%C There is no further term up to 5*10^17. 1008001 is the only known palprime which has two representations of the form m*reversal(m)+1 (m > reversal(m)).

%H Carlos Rivera,<a href="http://www.primepuzzles.net/puzzles/puzz_496.htm">P*R(P)+1 = Palprime</a>

%t r[n_]:=FromDigits[Reverse[IntegerDigits[n]]];Do[If[m>=r[m]&&PrimeQ[m r[m]+1] && r[m r[m]+1]==m r[m]+1,Print[m r[m]+1]],{m,710000000}]

%Y Cf. A158997, A177856.

%K base,more,nonn

%O 1,1

%A _Farideh Firoozbakht_, Jul 09 2009

%E Cross-reference fixed by _Franklin T. Adams-Watters_, May 14 2010