cp's OEIS Frontend

A107666 Primes having only {4, 6, 9} as digits.

%I A107666 #34 Jul 20 2025 17:59:33
%S A107666 449,499,4649,4969,4999,6449,6469,6949,9649,9949,44449,44699,46499,
%T A107666 46649,49499,49669,49999,64499,64969,66449,66499,66949,69499,94649,
%U A107666 94949,94999,96469,99469,444449,444469,444649,446969,449699,464699,464999,466649,469649,469969
%N A107666 Primes having only {4, 6, 9} as digits.
%C A107666 Intersection of A000040 and A107665. - _K. D. Bajpai_, Sep 08 2014
%H A107666 Jason Bard, <a href="/A107666/b107666.txt">Table of n, a(n) for n = 1..10000</a> (first 2069 terms from K. D. Bajpai)
%H A107666 <a href="/index/Pri#PrimesWithDigits">Index to entries for primes with digits in a given set</a>
%e A107666 From _K. D. Bajpai_, Sep 08 2014: (Start)
%e A107666 4649 is a term because it is a prime having only semiprime digits 4, 6 and 9.
%e A107666 6469 is a term because it is a prime having only semiprime digits 4, 6 and 9.
%e A107666 449 is the smallest prime comprising only semiprime digits 4, 6 or 9.
%e A107666 (End)
%p A107666 N:= 4:  Dgts:= {4, 6, 9}:  A:= NULL:
%p A107666 for d from 1 to N do
%p A107666 K:= combinat[cartprod]([Dgts minus {0}, Dgts $(d-1)]);
%p A107666 while not K[finished] do L:= K[nextvalue]();  x:= add(L[i]*10^(d-i), i=1..d);
%p A107666 if isprime(x) then A:= A, x fi od od: A;  # _K. D. Bajpai_, Sep 08 2014
%t A107666 Select[Prime[Range[50000]], Intersection[IntegerDigits[#], {0, 1, 2, 3, 5, 7, 8}] == {} &] (* _K. D. Bajpai_, Sep 08 2014 *)
%Y A107666 Cf. A107665 (numbers with semiprime digits), A001358 (semiprimes), A051416 (primes whose digits are all composite), A020466 (primes with digits 4 and 9 only), A093402 (primes of form 44...9), A093945 (primes of form 499...).
%Y A107666 Cf. A107342, A111494, A111496, A111697.
%Y A107666 Cf. A385768 - A385800.
%K A107666 base,nonn
%O A107666 1,1
%A A107666 _Rick L. Shepherd_, May 19 2005
%E A107666 a(35)-a(38) from _K. D. Bajpai_, Sep 08 2014