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 1-10 of 13 results. Next

A260380 Primes having only {3, 6, 7} as digits.

Original entry on oeis.org

3, 7, 37, 67, 73, 337, 367, 373, 673, 677, 733, 773, 3373, 3637, 3673, 3677, 3733, 3767, 6337, 6367, 6373, 6637, 6673, 6733, 6737, 6763, 7333, 7673, 33377, 33637, 33767, 33773, 36373, 36637, 36677, 36767, 37337, 37363, 37633, 37663, 63337, 63367, 63377, 63667
Offset: 1

Views

Author

Vincenzo Librandi, Aug 01 2015

Keywords

Comments

A020463 and A020469 are subsequences.

Crossrefs

Cf. similar sequences listed in A260378.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [3, 6, 7]];
  • Mathematica
    Select[Prime[Range[2 10^4]], Complement[IntegerDigits[#], {3, 6, 7}]=={} &]
    Select[Flatten[Table[FromDigits/@Tuples[{3,6,7},n],{n,5}]],PrimeQ] (* Harvey P. Dale, Apr 13 2022 *)

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}] == {} &]

A260891 Primes having only {1, 6, 7} as digits.

Original entry on oeis.org

7, 11, 17, 61, 67, 71, 167, 617, 661, 677, 761, 1117, 1171, 1667, 1777, 6661, 6761, 7177, 7717, 11117, 11161, 11171, 11177, 11617, 11677, 11717, 11777, 16111, 16661, 17117, 17167, 17761, 61667, 61717, 66161, 66617, 67777, 71161, 71167, 71171, 71671
Offset: 1

Views

Author

Vincenzo Librandi, Aug 05 2015

Keywords

Comments

A020454, A020455 and A020469 are subsequences.

Crossrefs

Cf, similar sequences listed in A260889.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [1, 6, 7]];
  • Mathematica
    Select[Prime[Range[2 10^4]], Complement[IntegerDigits[#], {1, 6, 7}] == {} &]

A261184 Primes having only {6, 7, 9} as digits.

Original entry on oeis.org

7, 67, 79, 97, 677, 769, 797, 967, 977, 997, 6679, 6779, 6967, 6977, 6997, 7669, 7699, 9677, 9679, 9697, 9767, 9769, 9967, 66697, 66797, 66977, 67679, 67699, 67777, 67967, 67979, 69677, 69697, 69767, 69779, 69997, 76667, 76679, 76697, 76777, 77699, 77797
Offset: 1

Views

Author

Vincenzo Librandi, Aug 11 2015

Keywords

Comments

A020469 and A020471 are subsequences.

Crossrefs

Cf. similar sequences listed in A261181.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^5) | Set(Intseq(p)) subset [6, 7, 9]];
  • Mathematica
    Select[Prime[Range[6 10^4]], Complement[IntegerDigits[#], {6, 7, 9}] == {} &]
    Select[Flatten[Table[FromDigits/@Tuples[{6,7,9},n],{n,5}]],PrimeQ] (* Harvey P. Dale, Jun 18 2021 *)

A385770 Primes having only {0, 6, 7} as digits.

Original entry on oeis.org

7, 67, 607, 677, 6007, 6067, 6607, 7607, 60077, 60607, 66067, 67607, 67777, 70067, 70607, 70667, 76607, 76667, 76777, 606077, 606607, 607007, 607067, 607667, 660067, 660607, 666067, 666607, 666667, 666707, 670777, 676007, 677077, 677767, 700067
Offset: 1

Views

Author

Jason Bard, Jul 09 2025

Keywords

Examples

			6007 is a term because it is prime and has only {0,6,7} as digits.
		

Crossrefs

Subsequence of A030432.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [0, 6, 7]];
    
  • Mathematica
    Select[FromDigits/@Tuples[{0,6,7},5],PrimeQ]
  • PARI
    primes_with(, 1, [0, 6, 7]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("067"), 41))) # uses function/imports in A385776
    

A385787 Primes having only {2, 6, 7} as digits.

Original entry on oeis.org

2, 7, 67, 227, 277, 677, 727, 2267, 2677, 2767, 2777, 6277, 7727, 22277, 22727, 22777, 26227, 26267, 26627, 26777, 27277, 27767, 62627, 67777, 72227, 72277, 72727, 72767, 76667, 76777, 77267, 226267, 226777, 227267, 227627, 262627, 266677, 266767, 267227
Offset: 1

Views

Author

Jason Bard, Jul 13 2025

Keywords

Crossrefs

Supersequence of A020459, A020469.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [2, 6, 7]];
    
  • Mathematica
    Flatten[Table[Select[FromDigits /@ Tuples[{2, 6, 7}, n], PrimeQ], {n, 7}]]
  • PARI
    primes_with(, 1, [2, 6, 7]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("267"), 41))) # uses function/imports in A385776
    

A385794 Primes having only {4, 6, 7} as digits.

Original entry on oeis.org

7, 47, 67, 467, 647, 677, 4447, 7477, 44647, 44777, 46447, 46477, 46747, 47777, 64667, 64747, 66467, 67447, 67477, 67777, 74747, 76667, 76777, 77447, 77477, 77647, 77747, 444677, 444767, 446447, 446477, 446647, 446767, 447467, 447677, 464447, 464467, 464647, 464747
Offset: 1

Views

Author

Jason Bard, Jul 13 2025

Keywords

Crossrefs

Subsequence of A030432.
Supersequence of A020465, A020469.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [4, 6, 7]];
    
  • Mathematica
    Flatten[Table[Select[FromDigits /@ Tuples[{4, 6, 7}, n], PrimeQ], {n, 7}]]
  • PARI
    primes_with(, 1, [4, 6, 7]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("467"), 41))) # uses function/imports in A385776
    

A385799 Primes having only {6, 7, 8} as digits.

Original entry on oeis.org

7, 67, 677, 787, 877, 887, 7687, 7867, 7877, 8677, 8867, 8887, 66877, 67777, 67867, 68687, 68767, 68777, 76667, 76777, 77687, 77867, 78787, 78877, 78887, 86677, 86767, 87767, 87877, 87887, 88667, 88867, 666667, 667687, 667867, 668677, 668687, 668867, 677687, 677767
Offset: 1

Views

Author

Jason Bard, Jul 14 2025

Keywords

Crossrefs

Subsequence of A030432, A106111.
Supersequence of A020469, A020470.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [6, 7, 8]];
    
  • Mathematica
    Flatten[Table[Select[FromDigits /@ Tuples[{6, 7, 8}, n], PrimeQ], {n, 7}]]
  • PARI
    primes_with(, 1, [6, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("678"), 41))) # uses function/imports in A385776
    

A036322 Composite numbers whose prime factors contain no digits other than 6 and 7.

Original entry on oeis.org

49, 343, 469, 2401, 3283, 4489, 4739, 16807, 22981, 31423, 33173, 45359, 117649, 160867, 219961, 232211, 300763, 317513, 458329, 474439, 536669, 537439, 823543, 1126069, 1539727, 1625477, 2105341, 2222591, 3039053, 3208303, 3321073
Offset: 1

Views

Author

Patrick De Geest, Dec 15 1998

Keywords

Comments

The multiplicative closure of A020469 consists of itself, 1, and this sequence. - Charles R Greathouse IV, Jun 25 2014

Crossrefs

Formula

Sum_{n>=1} 1/a(n) = Product_{p in A020469} (p/(p - 1)) - Sum_{p in A020469} 1/p - 1 = 0.0268448443... . - Amiram Eldar, May 22 2022

A036948 Smallest n-digit prime containing only the digits 6 and 7, or 0 if no such prime exists.

Original entry on oeis.org

7, 67, 677, 0, 67777, 666667, 6676667, 66666667, 666666667, 6666666767, 66666666667, 666666676667, 6666666667777, 66666667677767, 666666666667777, 6666666666767777, 66666666666667667, 666666666666676667
Offset: 1

Views

Author

Patrick De Geest, Jan 04 1999

Keywords

Crossrefs

Programs

  • Mathematica
    Table[SelectFirst[10#+7&/@FromDigits/@Tuples[{6,7},n],PrimeQ],{n,0,17}]/. (Missing["NotFound"]->0) (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Apr 08 2019 *)
Showing 1-10 of 13 results. Next