This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A073041 #8 Jul 05 2020 17:27:29 %S A073041 2,12,21,30,36,60,63,90,114,132,150,162,174,192,198,204,231,237,240, %T A073041 246,255,261,264,291,306,330,360,378,390,402,411,420,438,447,456,462, %U A073041 471,477,495,510,552,588,594,603,609,627,630,642,654,669,690,726,732 %N A073041 n*R(n)-1 is prime, where R(n) is reverse of n. %C A073041 From _Robert Israel_, Jul 25 2019: (Start) %C A073041 If n is in the sequence and is not divisible by 10, then A004086(n) is in the sequence. %C A073041 All terms except 2 are divisible by 3. (End) %H A073041 Robert Israel, <a href="/A073041/b073041.txt">Table of n, a(n) for n = 1..10000</a> %e A073041 12 is a term because 12*21-1=251 is prime. %p A073041 revdigs:= proc(n) local L,i; %p A073041 L:= convert(n,base,10); %p A073041 add(L[-i]*10^(i-1),i=1..nops(L)) %p A073041 end proc: %p A073041 select(t -> isprime(t*revdigs(t)-1), [$1..1000]); # _Robert Israel_, Jul 25 2019 %t A073041 Select[Range[800],PrimeQ[# IntegerReverse[#]-1]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Jul 05 2020 *) %Y A073041 Cf. A004086, A061205. %K A073041 easy,base,nonn %O A073041 1,1 %A A073041 _Shyam Sunder Gupta_, Aug 23 2002