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Primes having only the (decimal) digits 3, 4 and 8.
3

%I #8 Apr 09 2022 16:52:35

%S 3,43,83,383,433,443,883,3343,3433,3833,4483,8443,33343,34483,34843,

%T 34883,38333,38833,44383,44483,44843,48383,48883,83383,83443,83833,

%U 83843,84443,88843,88883,333383,333433,334333,334843,338383,343333,343433,344483,344843,348433,348443,348833,348883,383483,383833,384343,384383,388483

%N Primes having only the (decimal) digits 3, 4 and 8.

%C All terms end in 3 and those > 3 never have the same number of 4's and 8's.

%H Harvey P. Dale, <a href="/A199348/b199348.txt">Table of n, a(n) for n = 1..1000</a>

%t Table[Select[FromDigits/@Tuples[{3,4,8},n],PrimeQ],{n,6}]//Flatten (* _Harvey P. Dale_, Apr 09 2022 *)

%o (PARI) a(n, list=0, L=[3, 4, 8], reqpal=0)={my(t); for(d=1, 1e9, u=vector(d, i, 10^(d-i))~; forvec(v=vector(d, i, [1+(i==1&!L[1]), #L]), isprime(t=vector(d, i, L[v[i]])*u) || next; reqpal & !isprime(A004086(t)) & next; list & print1(t", "); n--|return(t)))}

%Y Cf. A020449 - A020472, A199325 - A199329.

%K nonn,base

%O 1,1

%A _M. F. Hasler_, Nov 05 2011