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A345472 Emirps p such that both p and its reversal are sums of three consecutive primes. 1

%I #14 Jun 21 2021 23:31:25

%S 1151,1249,1511,3467,3697,7643,7963,9421,11593,32749,36467,39511,

%T 71329,76463,92317,94723,110119,111109,123707,124309,124823,128377,

%U 141371,146953,150383,155153,160159,164291,167779,173141,178223,184609,190807,192383,192461,199247,304193,304879,306133,322871

%N Emirps p such that both p and its reversal are sums of three consecutive primes.

%C Numbers p such that p and its digit reversal are distinct members of A034962.

%H Robert Israel, <a href="/A345472/b345472.txt">Table of n, a(n) for n = 1..1792</a>

%e a(4) = 1511 because 1511 and its reversal 1151 are distinct primes, and 1511 = 499+503+509 and 1151 = 379+383+389 are sums of three consecutive primes.

%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:= select(isprime, [2,seq(i,i=3..nextprime(nextprime(333333)),2)]):

%p P3:= convert(select(isprime,P[1..-3]+P[2..-2]+P[3..-1]),set):

%p B:= P3 intersect map(digrev,P3):

%p sort(convert(remove(t -> digrev(t)=t,B),list);

%Y Cf. A006567, A034962.

%K nonn,base

%O 1,1

%A _J. M. Bergot_ and _Robert Israel_, Jun 20 2021

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Last modified April 18 03:01 EDT 2024. Contains 371767 sequences. (Running on oeis4.)