Search: id:A076611
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%I A076611
%S A076611 2,3,5,7,131,151,353,373,727,757,929,10301,10501,11311,12721,13331,
%T A076611 14341,14741,15551,16361,16561,19391,30203,30703,31513,32323,33533,
%U A076611 34543,35353,35753,36263,36563,37273,37573,38783,39293,70207,70507
%N A076611 Palindromic primes with prime middle digit.
%C A076611 There are no such numbers with an even number of digits. This sequence 
               is quite similar to the sequence A071119 up to 12th term.
%e A076611 a(12)=10301 is palindromic prime and its middle digit 3 is prime, a(13)=10501 
               is palindromic prime and its middle digit 5 is prime, a(14)=11311 
               is palindromic prime and its middle digit 3 is prime, ...
%p A076611 ts_numprapal := proc(n) local ad,adr,midigit; ad := convert(n,base,10): 
               adr := ListTools[Reverse](ad): if nops(ad) mod 2 = 0 then return 
               1; fi; midigit := op( (nops(ad)+1)/2,ad ): if (isprime( midigit )='true' 
               and adr=ad) then return 0; else return 1; fi end: ts_pra_num_pal 
               := proc(n) local p1; p1 := ithprime(n): if ts_numprapal(p1) = 0 then 
               return (p1) fi end: apranumpal := [seq(ts_pra_num_pal(i), i=1..100000)]: 
               apranumpal;
%Y A076611 Cf. A002385, A069217, A071119.
%Y A076611 Sequence in context: A090718 A117703 A039944 this_sequence A082805 A071119 
               A157869
%Y A076611 Adjacent sequences: A076608 A076609 A076610 this_sequence A076612 A076613 
               A076614
%K A076611 easy,nonn,base
%O A076611 1,1
%A A076611 Jani Melik (jani_melik(AT)hotmail.com), Oct 21 2002

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