A261182 Primes that contain only the digits (2, 7, 9).

2, 7, 29, 79, 97, 227, 229, 277, 727, 797, 929, 977, 997, 2297, 2729, 2777, 2797, 2927, 2999, 7229, 7297, 7727, 7927, 9227, 9277, 9929, 22229, 22277, 22279, 22727, 22777, 27277, 27299, 27779, 27799, 27997, 29297, 29927, 72227, 72229, 72277, 72727, 72797

Offset

1,1

Comments

A020459, A020460 and A020471 are subsequences.

Links

Chai Wah Wu, Table of n, a(n) for n = 1..1000

Mathematica

Select[Prime[Range[2 10^4]], Complement[IntegerDigits[#], {2, 7, 9}] == {} &]
Select[Flatten[Table[FromDigits/@Tuples[{2, 7, 9}, n], {n, 5}]], PrimeQ] (* Harvey P. Dale, Dec 17 2024 *)

Prog

(Magma) [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [2, 7, 9]];
(Python)
from gmpy2 import is_prime
from itertools import product
A261182_list = [int(''.join(d)) for l in range(1, 10) for d in product('279', repeat=l) if is_prime(int(''.join(d)))] # Chai Wah Wu, Aug 11 2015

Crossrefs

Cf. similar sequences listed in A261181.

Cf. A000040, A020459, A020460, A020471.

Sequence in context: A158024 A166940 A166939 * A155186 A203969 A199581

Adjacent sequences: A261179 A261180 A261181 * A261183 A261184 A261185

Keyword

nonn,easy,base

Author

Vincenzo Librandi, Aug 11 2015

Status

approved