This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A260889 #18 Jul 20 2025 22:28:37
%S A260889 2,7,11,17,71,127,211,227,271,277,727,1117,1171,1217,1277,1721,1777,
%T A260889 2111,2221,2711,2777,7121,7127,7177,7211,7717,7727,11117,11171,11177,
%U A260889 11717,11777,12211,12227,12277,12721,17117,21121,21211,21221,21227,21277,21727
%N A260889 Primes having only {1, 2, 7} as digits.
%C A260889 A020450, A020455 and A020459 are subsequences.
%H A260889 Alois P. Heinz, <a href="/A260889/b260889.txt">Table of n, a(n) for n = 1..10000</a>
%H A260889 <a href="/index/Pri#PrimesWithDigits">Index to entries for primes with digits in a given set</a>
%t A260889 Select[Prime[Range[2 10^5]], Complement[IntegerDigits[#], {1, 2, 7}] == {} &]
%t A260889 Table[Select[FromDigits/@Tuples[{1,2,7},n],PrimeQ],{n,5}]//Flatten (* _Harvey P. Dale_, Apr 12 2018 *)
%o A260889 (Magma) [p: p in PrimesUpTo(3*10^4) | Set(Intseq(p)) subset [1, 2, 7]];
%Y A260889 Cf. Primes that contain only the digits (k,1,7): A199327 (k=0), this sequence (k=2), A260379 (k=3), A079651 (k=4), A260828 (k=5), A260891 (k=6), A260892 (k=8), A260893 (k=9).
%Y A260889 Cf. A020450, A020455, A020459.
%K A260889 nonn,easy,base
%O A260889 1,1
%A A260889 _Vincenzo Librandi_, Aug 04 2015