|
%I #58 Sep 08 2022 08:46:24
%S 101,103,107,109,307,401,503,509,601,607,701,709,809,907,11071,11087,
%T 11093,12037,12049,12097,13099,14029,14033,14051,14071,14081,14083,
%U 14087,15031,15053,15083,16057,16063,16067,16069,16097,17021,17033,17041,17047,17053
%N Cyclops primes that remain prime after being "blinded".
%C There are 14 of these primes with 3 digits and 302 with 5 digits.
%H Rodolfo Ruiz-Huidobro, <a href="/A329737/b329737.txt">Table of n, a(n) for n = 1..3194</a>
%e The first term, a(1), is 101 because if you remove the "cyclops' eye" it remains a prime (11) and because 101 is the 1st cyclops prime.
%e 307 is a term because when you remove the "0" it remains a prime: 37.
%o (Magma) a:=[]; f:=func<n|IsPrime(n) and IsOdd(#a) and a[(#a+1) div 2] eq 0 and not 0 in a[1..(#a-1) div 2] cat a[(#a+3) div 2..#a] where a is Intseq(n)>; g:=func<n|Seqint(a[1..(#a-1) div 2] cat a[(#a+3) div 2..#a]) where a is Intseq(n)>; for n in [1..20000] do if f(n) and IsPrime(g(n)) then Append(~a,n); end if; end for; a; // _Marius A. Burtea_, Nov 20 2019
%Y Intersection of A256186 and A134809.
%K nonn,base,easy
%O 1,1
%A _Rodolfo Ruiz-Huidobro_, Nov 20 2019
|
