login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Primes whose reversal is a multiple of 13.
10

%I #13 Jul 20 2022 05:15:48

%S 19,31,269,281,397,401,457,463,523,773,827,1063,1117,1123,1367,1373,

%T 1427,1433,1489,1549,1609,1621,1871,1931,1987,1993,2027,2089,2161,

%U 2221,2399,2459,2531,2593,2647,2707,2713

%N Primes whose reversal is a multiple of 13.

%C There are no primes (besides 11) whose reversal is a multiple of 11.

%H Robert Israel, <a href="/A087764/b087764.txt">Table of n, a(n) for n = 1..10000</a>

%p digrev:= 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 B:= map(digrev, {seq(i,i=13..10000,13)}):

%p sort(convert(select(isprime, B),list)); # _Robert Israel_, Oct 23 2019

%o (PARI) forprime(n=2, 3000, if(fromdigits(Vecrev(digits(n)))%13==0, print1(n, ", "))) \\ _Mohammed Yaseen_, Jul 19 2022

%Y Primes whose reversal is a multiple of k: A087762 (k=7), this sequence (k=13), A087765 (k=17), A087766 (k=19), A087767 (k=23).

%K easy,nonn,base

%O 1,1

%A _Zak Seidov_, Oct 03 2003