A260889 Primes having only {1, 2, 7} as digits.

2, 7, 11, 17, 71, 127, 211, 227, 271, 277, 727, 1117, 1171, 1217, 1277, 1721, 1777, 2111, 2221, 2711, 2777, 7121, 7127, 7177, 7211, 7717, 7727, 11117, 11171, 11177, 11717, 11777, 12211, 12227, 12277, 12721, 17117, 21121, 21211, 21221, 21227, 21277, 21727

Offset: 1

Author

Vincenzo Librandi, Aug 04 2015

Keywords

• nonn
• easy
• base

Comments

A020450, A020455 and A020459 are subsequences.

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..10000
• Index to entries for primes with digits in a given set

Crossrefs

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).

Cf. A020450, A020455, A020459.

Programs

Magma

[p: p in PrimesUpTo(3*10^4) | Set(Intseq(p)) subset [1, 2, 7]];

Mathematica

Select[Prime[Range[2 10^5]], Complement[IntegerDigits[#], {1, 2, 7}] == {} &]
Table[Select[FromDigits/@Tuples[{1,2,7},n],PrimeQ],{n,5}]//Flatten (* Harvey P. Dale, Apr 12 2018 *)