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.

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A181605 Twin primes ending in 7.

Original entry on oeis.org

7, 17, 107, 137, 197, 227, 347, 617, 827, 857, 1277, 1427, 1487, 1607, 1667, 1697, 1787, 1877, 1997, 2027, 2087, 2237, 2267, 2657, 2687, 3167, 3257, 3467, 3527, 3557, 3767, 3917, 4127, 4157, 4217, 4337, 4517, 4547, 4637, 4787, 4967, 5417, 5477, 5657
Offset: 1

Views

Author

Omar E. Pol, Nov 01 2010

Keywords

Comments

First disagrees with A092340 at n=26: A092340 contains 2707, but this sequence doesn't. Is this a subsequence of A092340? - Nathaniel Johnston, Jun 25 2011
Yes, it is a subsequence of A092340: see link. - Robert Israel, Apr 13 2021

Crossrefs

Programs

  • Maple
    [7, op(select(t -> isprime(t) and isprime(t+2), [seq(i,i=17..10000,30)]))]; # Robert Israel, Apr 13 2021
  • Mathematica
    Select[Prime@ Range@ 800, Mod[ #, 10] == 7 && (PrimeQ[ # - 2] || PrimeQ[ # + 2]) &] (* Robert G. Wilson v, Nov 06 2010 *)

Formula

A001097 INTERSECT A030432. - R. J. Mathar, Nov 03 2010

Extensions

More terms from R. J. Mathar and Robert G. Wilson v, Nov 03 2010

A045380 Primes congruent to 2 mod 5.

Original entry on oeis.org

2, 7, 17, 37, 47, 67, 97, 107, 127, 137, 157, 167, 197, 227, 257, 277, 307, 317, 337, 347, 367, 397, 457, 467, 487, 547, 557, 577, 587, 607, 617, 647, 677, 727, 757, 787, 797, 827, 857, 877, 887, 907, 937, 947, 967, 977, 997, 1087, 1097, 1117, 1187, 1217, 1237
Offset: 1

Views

Author

Keywords

Crossrefs

Apart from the initial terms, essentially same as A030432 and A045357. Cf. A095022.

Programs

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
    

A385784 Primes having only {2, 4, 7} as digits.

Original entry on oeis.org

2, 7, 47, 227, 277, 727, 2447, 2477, 2777, 4447, 7247, 7477, 7727, 22247, 22277, 22447, 22727, 22777, 24247, 27277, 27427, 42227, 42727, 44777, 47777, 72227, 72277, 72727, 74747, 77447, 77477, 77747, 222247, 242227, 242447, 242747, 244247, 244747, 272227
Offset: 1

Views

Author

Jason Bard, Jul 13 2025

Keywords

Crossrefs

Supersequence of A020459, A020465.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [2, 4, 7]];
    
  • Mathematica
    Flatten[Table[Select[FromDigits /@ Tuples[{2, 4, 7}, n], PrimeQ], {n, 7}]]
  • PARI
    primes_with(, 1, [2, 4, 7]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("247"), 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
    

A385789 Primes having only {2, 7, 8} as digits.

Original entry on oeis.org

2, 7, 227, 277, 727, 787, 827, 877, 887, 2287, 2777, 2887, 7727, 7877, 8287, 8887, 22277, 22727, 22777, 22787, 22877, 27277, 27827, 28277, 72227, 72277, 72287, 72727, 78277, 78787, 78877, 78887, 82727, 82787, 87277, 87877, 87887, 222787, 222877, 227827, 228887
Offset: 1

Views

Author

Jason Bard, Jul 13 2025

Keywords

Crossrefs

Supersequence of A020459, A020470.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [2, 7, 8]];
    
  • Mathematica
    Flatten[Table[Select[FromDigits /@ Tuples[{2, 7, 8}, n], PrimeQ], {n, 7}]]
  • PARI
    primes_with(, 1, [2, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("278"), 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
    

A385795 Primes having only {4, 7, 8} as digits.

Original entry on oeis.org

7, 47, 487, 787, 877, 887, 4447, 4787, 4877, 7477, 7487, 7877, 8447, 8747, 8887, 44777, 44887, 47777, 48487, 48787, 48847, 74747, 74887, 77447, 77477, 77747, 78487, 78787, 78877, 78887, 84787, 87877, 87887, 88747, 444487, 444877, 444887, 447877, 474787, 474847
Offset: 1

Views

Author

Jason Bard, Jul 13 2025

Keywords

Crossrefs

Subsequence of A030432.
Supersequence of A020465, A020470.

Programs

  • Magma
    [p: p in PrimesUpTo(10^6) | Set(Intseq(p)) subset [4, 7, 8]];
    
  • Mathematica
    Flatten[Table[Select[FromDigits /@ Tuples[{4, 7, 8}, n], PrimeQ], {n, 7}]]
  • PARI
    primes_with(, 1, [4, 7, 8]) \\ uses function in A385776
  • Python
    print(list(islice(primes_with("478"), 41))) # uses function/imports in A385776
    

A045357 Primes congruent to {0, 2} mod 5.

Original entry on oeis.org

2, 5, 7, 17, 37, 47, 67, 97, 107, 127, 137, 157, 167, 197, 227, 257, 277, 307, 317, 337, 347, 367, 397, 457, 467, 487, 547, 557, 577, 587, 607, 617, 647, 677, 727, 757, 787, 797, 827, 857, 877, 887, 907, 937, 947, 967, 977, 997, 1087, 1097, 1117, 1187, 1217
Offset: 1

Views

Author

Keywords

Comments

Equivalently, primes congruent to {2,5,7} mod 10. [Bruno Berselli, Aug 07 2012]

Crossrefs

Apart from the initial terms essentially same as A030432 and A045380.

Programs

  • Magma
    [ p: p in PrimesUpTo(2000) | p mod 5 in {0, 2} ]; // Vincenzo Librandi, Aug 07 2012
  • Mathematica
    Select[Prime@Range[210], MemberQ[{0, 2}, Mod[ #, 5]] &] (* Ray Chandler, Jun 29 2008 *)

Extensions

Extended by Ray Chandler, Nov 07 2006

A384449 Primes having only {0, 4, 7} as digits.

Original entry on oeis.org

7, 47, 4007, 4447, 7477, 44777, 47407, 47777, 74047, 74077, 74707, 74747, 77047, 77447, 77477, 77747, 407047, 407707, 407747, 440047, 444007, 444047, 470077, 470447, 474077, 474707, 477047, 477077, 704447, 704477, 704747, 704777, 707407, 707747, 740477, 744077, 744407, 744707, 747407, 770047
Offset: 1

Views

Author

Jason Bard, May 29 2025

Keywords

Crossrefs

Subsequence of A030432.
Supersequence of A020465.
Cf. Primes that contain only the digits (0,k,7): A199327 (k=1), A261267 (k=2), A260378 (k=3), this sequence (k=4), A260827 (k=5), A261181 (k=9).
Cf. A000040.

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^6) | Set(Intseq(p)) subset [0, 4, 7]];
    
  • Mathematica
    Select[FromDigits/@Tuples[{0, 4, 7}, 6], PrimeQ]
  • Python
    from sympy import sieve
    A384449 = [p for p in sieve.primerange(10**6) if all(n in ['0','4','7'] for n in str(p))] # Jwalin Bhatt,  Jun 02 2025
    
  • Python
    from itertools import count, islice
    from gmpy2 import digits, is_prime
    def A384449_gen(): # generator of terms
        for i in count(1):
            if is_prime(m:=int(digits(i,3).replace('1','4').replace('2','7'))):
                yield m
    A384449_list = list(islice(A384449_gen(),40)) # Chai Wah Wu, Jun 07 2025
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