cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-9 of 9 results.

A260827 Primes having only {0, 5, 7} as digits.

Original entry on oeis.org

5, 7, 557, 577, 757, 5077, 5507, 5557, 7057, 7507, 7577, 7757, 50077, 50707, 50777, 55057, 57077, 57557, 70507, 75557, 75577, 75707, 77557, 500057, 500777, 505777, 507077, 507557, 507757, 550007, 550577, 550757, 555077, 555557, 555707, 557057, 570077, 575077
Offset: 1

Views

Author

Vincenzo Librandi, Aug 01 2015

Keywords

Crossrefs

A020467 is a subsequence.
Cf. Primes that contain only the digits (k,5,7): this sequence (k=0), A260828 (k=1), A214705 (k=2), A087363 (k=3), A217039 (k=4), A260829 (k=6), A260830 (k=8), A260831 (k=9).
Cf. A000040.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^6) | Set(Intseq(p)) subset [0,5,7]];
    
  • Mathematica
    Select[Prime[Range[2 10^5]], Complement[IntegerDigits[#], {0, 5, 7}]=={} &]
  • Python
    from sympy import isprime
    from sympy.utilities.iterables import multiset_permutations
    def aupton(terms):
      n, digits, alst = 0, 1, []
      while len(alst) < terms:
        mpstr = "".join(d*digits for d in "057")
        for mp in multiset_permutations(mpstr, digits):
          if mp[0] == "0": continue
          t = int("".join(mp))
          if isprime(t): alst.append(t)
          if len(alst) == terms: break
        else: digits += 1
      return alst
    print(aupton(38)) # Michael S. Branicky, May 07 2021

A260831 Primes having only {5, 7, 9} as digits.

Original entry on oeis.org

5, 7, 59, 79, 97, 557, 577, 599, 757, 797, 977, 997, 5557, 5779, 7559, 7577, 7757, 7759, 55579, 55799, 55997, 57557, 57559, 57977, 59557, 59779, 59797, 59957, 59999, 75557, 75577, 75797, 75979, 75997, 77557, 77797, 77977, 77999, 79559, 79579, 79757, 79777
Offset: 1

Views

Author

Vincenzo Librandi, Aug 03 2015

Keywords

Comments

A020467, A020468 and A020471 are subsequences.
Subsequence of A030096.

Crossrefs

Cf. similar sequences listed in A260827.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [5, 7, 9]];
  • Mathematica
    Select[Prime[Range[2 10^5]], Complement[IntegerDigits[#], {5, 7, 9}] == {} &]

A260828 Primes having only {1, 5, 7} as digits.

Original entry on oeis.org

5, 7, 11, 17, 71, 151, 157, 557, 571, 577, 751, 757, 1117, 1151, 1171, 1511, 1571, 1777, 5171, 5557, 5711, 5717, 7151, 7177, 7517, 7577, 7717, 7757, 11117, 11171, 11177, 11551, 11717, 11777, 15511, 15551, 17117, 17551, 51151, 51157, 51511, 51517, 51551, 51577
Offset: 1

Views

Author

Vincenzo Librandi, Aug 02 2015

Keywords

Crossrefs

Subsequence of A030096. A020453, A020455 and A020467 are subsequences.
Cf. similar sequences listed in A260827.
Cf. A000040.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [1,5,7]];
    
  • Mathematica
    Select[Prime[Range[2 10^4]], Complement[IntegerDigits[#], {1, 5, 7}] == {} &]
  • Python
    from sympy import isprime
    from sympy.utilities.iterables import multiset_permutations
    def aupton(terms):
      n, digits, alst = 0, 1, []
      while len(alst) < terms:
        mpstr = "".join(d*digits for d in "157")
        for mp in multiset_permutations(mpstr, digits):
          t = int("".join(mp))
          if isprime(t): alst.append(t)
          if len(alst) == terms: break
        else: digits += 1
      return alst
    print(aupton(44)) # Michael S. Branicky, May 07 2021

A260829 Primes having only {5, 6, 7} as digits.

Original entry on oeis.org

5, 7, 67, 557, 577, 677, 757, 5557, 5657, 6577, 7577, 7757, 55667, 56767, 57557, 57667, 65557, 65657, 65677, 65777, 67567, 67577, 67757, 67777, 75557, 75577, 75767, 76667, 76757, 76777, 77557, 555557, 555677, 555767, 557567, 565567, 565667, 566557, 566567
Offset: 1

Views

Author

Vincenzo Librandi, Aug 02 2015

Keywords

Comments

A020467 and A020469 are subsequences.

Crossrefs

Cf. similar sequences listed in A260827.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^6) | Set(Intseq(p)) subset [5,6,7]];
  • Mathematica
    Select[Prime[Range[2 10^5]], Complement[IntegerDigits[#], {5, 6, 7}] == {} &]

A260830 Primes having only {5, 7, 8} as digits.

Original entry on oeis.org

5, 7, 557, 577, 587, 757, 787, 857, 877, 887, 5557, 5857, 7577, 7757, 7877, 8887, 55787, 57557, 57587, 57787, 58757, 58787, 75557, 75577, 75787, 77557, 77587, 78577, 78787, 78857, 78877, 78887, 85577, 87557, 87587, 87877, 87887, 555557, 555857, 557857, 558587
Offset: 1

Views

Author

Vincenzo Librandi, Aug 02 2015

Keywords

Comments

A020467 and A020470 are subsequences.

Crossrefs

Cf. similar sequences listed in A260827.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^6) | Set(Intseq(p)) subset [5,7,8]];
  • Mathematica
    Select[Prime[Range[2 10^5]], Complement[IntegerDigits[#], {5, 7, 8}] == {} &]
    Select[Flatten[Table[FromDigits/@Tuples[{5,7,8},n],{n,6}]],PrimeQ] (* Harvey P. Dale, Oct 06 2017 *)

A284380 Numbers k with digits 5 and 7 only.

Original entry on oeis.org

5, 7, 55, 57, 75, 77, 555, 557, 575, 577, 755, 757, 775, 777, 5555, 5557, 5575, 5577, 5755, 5757, 5775, 5777, 7555, 7557, 7575, 7577, 7755, 7757, 7775, 7777, 55555, 55557, 55575, 55577, 55755, 55757, 55775, 55777, 57555, 57557, 57575, 57577, 57755, 57757
Offset: 1

Views

Author

Jaroslav Krizek, Mar 28 2017

Keywords

Crossrefs

Prime terms are in A020467.
Numbers n with digits 5 and k only for k = 0 - 4 and 6 - 9: A169964 (k = 0), A276037 (k = 1), A072961 (k = 2), A284379 (k = 3), A256290 (k = 4), A256291 (k = 6), this sequence (k = 7), A284381 (k = 8), A284382 (k = 9).

Programs

  • Magma
    [n: n in [1..100000] | Set(IntegerToSequence(n, 10)) subset {5, 7}];
    
  • Mathematica
    Join @@ ((FromDigits /@ Tuples[{5, 7}, #]) & /@ Range@ 5) (* Giovanni Resta, Mar 28 2017 *)
  • Python
    from sympy.utilities.iterables import multiset_permutations
    def aupton(terms):
      n, digits, alst = 0, 1, []
      while len(alst) < terms:
        mpstr = "".join(d*digits for d in "57")
        for mp in multiset_permutations(mpstr, digits):
          alst.append(int("".join(mp)))
          if len(alst) == terms: break
        else: digits += 1
      return alst
    print(aupton(44)) # Michael S. Branicky, May 07 2021

A036320 Composite numbers whose prime factors contain no digits other than 5 and 7.

Original entry on oeis.org

25, 35, 49, 125, 175, 245, 343, 625, 875, 1225, 1715, 2401, 2785, 2885, 3125, 3785, 3899, 4039, 4375, 5299, 6125, 8575, 12005, 13925, 14425, 15625, 16807, 18925, 19495, 20195, 21875, 26495, 27293, 27785, 28273, 30625, 37093, 37885, 38785
Offset: 1

Views

Author

Patrick De Geest, Dec 15 1998

Keywords

Comments

All terms are a product of at least two terms of A020467. - David A. Corneth, Oct 09 2020

Crossrefs

Formula

Sum_{n>=1} 1/a(n) = Product_{p in A020467} (p/(p - 1)) - Sum_{p in A020467} 1/p - 1 = 0.1179595738... . - Amiram Eldar, May 22 2022

A036946 Smallest n-digit prime containing only the digits 5 and 7, or 0 if no such prime exists.

Original entry on oeis.org

5, 0, 557, 5557, 57557, 555557, 5555777, 55555777, 555557557, 5555555557, 55555555777, 555555575557, 5555555757757, 55555555575757, 555555555555557, 5555555555557577, 55555555555777777, 555555555557557757, 5555555555555557577, 55555555555575755777
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Crossrefs

Programs

  • Mathematica
    Flatten[Join[{5,0},Table[Select[FromDigits/@(Join[#,{7}]&/@Tuples[ {5,7},n]), PrimeQ,1],{n,2,20}]]] (* Harvey P. Dale, Mar 08 2013 *)

Extensions

More terms from Harvey P. Dale, Mar 08 2013

A386351 Primes without {5, 7} as digits.

Original entry on oeis.org

2, 3, 11, 13, 19, 23, 29, 31, 41, 43, 61, 83, 89, 101, 103, 109, 113, 131, 139, 149, 163, 181, 191, 193, 199, 211, 223, 229, 233, 239, 241, 263, 269, 281, 283, 293, 311, 313, 331, 349, 383, 389, 401, 409, 419, 421, 431, 433, 439, 443, 449, 461, 463, 491, 499
Offset: 1

Views

Author

Jason Bard, Jul 20 2025

Keywords

Crossrefs

Intersection of A038613 and A038615.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 1, 2, 3, 4, 6, 8, 9]];
    
  • Mathematica
    Select[Prime[Range[120]], DigitCount[#, 10, 5] == 0 && DigitCount[#, 10, 7] == 0 &]
  • PARI
    primes_with(, 1, [0, 1, 2, 3, 4, 6, 8, 9]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("01234689"), 41))) # uses function/imports in A385776
    
Showing 1-9 of 9 results.