A199327 Primes having only {0, 1, 7} as digits.

7, 11, 17, 71, 101, 107, 701, 1117, 1171, 1777, 7001, 7177, 7717, 10007, 10111, 10177, 10711, 10771, 11071, 11117, 11171, 11177, 11701, 11717, 11777, 17011, 17077, 17107, 17117, 17707, 70001, 70111, 70117, 70177, 70717, 71011, 71171, 71707, 71711, 71777, 77017, 77101, 77171, 77711, 101107, 101111, 101117

Offset: 1

Author

M. F. Hasler, Nov 05 2011

Keywords

• nonn
• base

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..10000
• James Maynard and Brady Haran, Primes without a 7, Numberphile video (2019).

Crossrefs

Cf. A020449 - A020472, A036953, A260044, A260267 - A260271, A199325 - A199329, A061247, A199340 - A199349.

Programs

Magma

[p: p in PrimesUpTo(80000) | Intseq(p) subset {0,1,7}]; // Vincenzo Librandi, Jan 16 2020

Mathematica

f[i_,nn_]:=Select[Flatten[Table[FromDigits/@(Join[{i},#]&/@Tuples[ {0,1,7}, n]), {n,0,nn}]],PrimeQ]; Union[Join[f[1,6],f[7,6]]] (* Harvey P. Dale, Nov 19 2011 *)
Select[Prime[Range[2 10^4]], Complement[IntegerDigits[#], {0, 1, 7}]=={}&] (* Vincenzo Librandi, Jan 16 2020 *)

PARI

a(n,list=0,L=[0,1,7])={for(d=1,1e9,my(t,u=vector(d,i,10^(d-i))~);forvec(v=vector(d,i,[1+!(L[1]||(i>1&&iM. F. Hasler, Jul 26 2015