login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Primes that contain only the digits (1, 3, 7).
3

%I #15 Dec 09 2024 14:27:55

%S 3,7,11,13,17,31,37,71,73,113,131,137,173,311,313,317,331,337,373,733,

%T 773,1117,1171,1373,1733,1777,3137,3313,3331,3371,3373,3733,7177,7331,

%U 7333,7717,11113,11117,11131,11171,11173,11177,11311,11317,11717,11731,11777

%N Primes that contain only the digits (1, 3, 7).

%H Alois P. Heinz, <a href="/A260379/b260379.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[Prime[Range[2 10^3]], Complement[IntegerDigits[#], {1, 3, 7}]=={} &]

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

%Y Subsequence of A030096 and A155055. A020451, A020455, and A020463 are subsequences.

%Y Cf. similar sequences listed in A260378.

%Y Cf. A000040, A020451, A020455, A020463.

%K nonn,easy,base,changed

%O 1,1

%A _Vincenzo Librandi_, Jul 24 2015