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 A217039 Primes whose decimal representation has only digits in {4,5,7}. 4
 5, 7, 47, 457, 547, 557, 577, 757, 4447, 4457, 4547, 5477, 5557, 7457, 7477, 7547, 7577, 7757, 44777, 45557, 45757, 47777, 54547, 54577, 55457, 55547, 57457, 57557, 74747, 75557, 75577, 77447, 77477, 77557, 77747, 444547, 444557, 445447, 445477, 445747, 447757 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS These could be called crooked primes. These are the primes in A214584. Primes all of whose numerals are written (san serif) with at least one right or acute angle. LINKS FORMULA A000040 INTERSECTION A214584. MATHEMATICA Select[Flatten[Table[FromDigits/@Tuples[{4, 5, 7}, n], {n, 6}]], PrimeQ] (* Bruno Berselli, Sep 25 2012 *) PROG (MAGMA) [p: p in PrimesUpTo(450000) | Intseq(p) subset [4, 5, 7]]; // Bruno Berselli, Sep 25 2012 (PARI) A217039(n=50, show=0, L=[4, 5, 7])={for(d=1, 1e9, my(t, u=vector(d, i, 10^(d-i))~); forvec(v=vector(d, i, [if(i==d&&d>1, 3/*must end in 7*/, 1), #L]), ispseudoprime(t=vecextract(L, v)*u)||next; show&&print1(t", "); n--||return(t)))} \\ Syntax updated for newer PARI versions by M. F. Hasler, Jul 25 2015 CROSSREFS Cf. A079651, A079652, A214584. Cf. A036953, A260044, A260267 - A260271, A199325 - A199329, A061247, A199340 - A199349. Sequence in context: A119787 A025530 A106114 * A299452 A110420 A210244 Adjacent sequences:  A217036 A217037 A217038 * A217040 A217041 A217042 KEYWORD nonn,base,easy AUTHOR Jonathan Vos Post, Sep 24 2012 STATUS approved

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Last modified September 29 11:42 EDT 2020. Contains 337431 sequences. (Running on oeis4.)