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 A091633 Primes whose digits are restricted to 1,3,7,9 (same as terminal digits of primes). 10

%I

%S 3,7,11,13,17,19,31,37,71,73,79,97,113,131,137,139,173,179,191,193,

%T 197,199,311,313,317,331,337,373,379,397,719,733,739,773,797,911,919,

%U 937,971,977,991,997,1117,1171,1193,1319,1373,1399,1733,1777,1913,1931,1933

%N Primes whose digits are restricted to 1,3,7,9 (same as terminal digits of primes).

%C Some primes of sufficient length might be termed DNA primes if the sequence of digits 1,3,7,9 in any order happens to be an appropriate analog of the DNA bases A, G, C, T. It would be interesting to know if it is possible for any DNA sequence to match a DNA prime.

%H Pierre Cami and Reinhard Zumkeller, <a href="/A091633/b091633.txt">Table of n, a(n) for n = 1..10000</a> (first 5058 terms from Pierre Cami)

%F Select primes having digits 1, 3, 7, 9 only.

%F a(n) = A000040(A091871(n)). - _R. J. Mathar_, Aug 29 2018

%t Select[Flatten[Table[FromDigits/@Tuples[{1,3,7,9},n],{n,4}]],PrimeQ] (* _Harvey P. Dale_, Jun 26 2015 *)

%o a091633 n = a091633_list !! (n-1)

%o a091633_list = filter ((== 1) . a010051') a136333_list

%o -- _Reinhard Zumkeller_, Jul 17 2014

%Y A091871 gives prime index.

%Y Cf. A010051, subsequence of A136333, A245193.

%K easy,nonn,base

%O 1,1

%A _Enoch Haga_, Jan 26 2004

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Last modified September 18 12:00 EDT 2019. Contains 327170 sequences. (Running on oeis4.)