%I #8 Jul 05 2020 17:27:29

%S 2,12,21,30,36,60,63,90,114,132,150,162,174,192,198,204,231,237,240,

%T 246,255,261,264,291,306,330,360,378,390,402,411,420,438,447,456,462,

%U 471,477,495,510,552,588,594,603,609,627,630,642,654,669,690,726,732

%N n*R(n)-1 is prime, where R(n) is reverse of n.

%C From _Robert Israel_, Jul 25 2019: (Start)

%C If n is in the sequence and is not divisible by 10, then A004086(n) is in the sequence.

%C All terms except 2 are divisible by 3. (End)

%H Robert Israel, <a href="/A073041/b073041.txt">Table of n, a(n) for n = 1..10000</a>

%e 12 is a term because 12*21-1=251 is prime.

%p revdigs:= proc(n) local L,i;

%p L:= convert(n,base,10);

%p add(L[-i]*10^(i-1),i=1..nops(L))

%p end proc:

%p select(t -> isprime(t*revdigs(t)-1), [$1..1000]); # _Robert Israel_, Jul 25 2019

%t Select[Range[800],PrimeQ[# IntegerReverse[#]-1]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jul 05 2020 *)

%Y Cf. A004086, A061205.

%K easy,base,nonn

%O 1,1

%A _Shyam Sunder Gupta_, Aug 23 2002