%I #14 Oct 30 2024 12:19:49

%S 1021,1087,1201,1223,1289,1447,1559,1627,2053,2143,2389,2503,2659,

%T 2749,3041,3221,3467,3557,3917,4051,4073,4231,4253,4297,4523,4567,

%U 4657,4679,4703,5443,5623,5689,5779,5869,6521,6701,6857,6947,7193,7283,7351,7621

%N Prime numbers in which the sum of the external digits = the sum of the internal digits.

%H Robert Israel, <a href="/A088290/b088290.txt">Table of n, a(n) for n = 1..10000</a>

%e 1021 is a member 1+1 = 0+2 = 2..

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

%p if not isprime(n) then return false fi;

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

%p L[1] + L[-1] = add(L[i],i=2..nops(L)-1)

%p end proc:

%p select(filter, [seq(i,i=101..10^4,2)]); # _Robert Israel_, Oct 30 2024

%t edidQ[n_]:=Module[{idn=IntegerDigits[n]},idn[[1]]+idn[[-1]]==Total[Most[ Rest[idn]]]]; Select[Prime[Range[169,3000]],edidQ] (* _Harvey P. Dale_, Apr 20 2012 *)

%Y Primes in A101317.

%Y Cf. A076167.

%K base,nonn

%O 1,1

%A _Amarnath Murthy_, Sep 29 2003

%E More terms from _David Wasserman_, Aug 04 2005

%E Offset changed by _Andrew Howroyd_, Sep 19 2024