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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A022013 Initial members of prime octuplets (p, p+6, p+8, p+14, p+18, p+20, p+24, p+26).

Original entry on oeis.org

88793, 284723, 855713, 1146773, 6560993, 69156533, 74266253, 218033723, 261672773, 302542763, 964669613, 1340301863, 1400533223, 1422475913, 1837160183, 1962038783, 2117861723, 2249363093, 2272018733, 2558211563
Offset: 1

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Author

Keywords

Comments

All terms are congruent to 173 (modulo 210). - Matt C. Anderson, May 26 2015

Crossrefs

A065706 is the union of A022011, A022012 and A022013.
A346998(n) = a(10^n).

Programs

  • Magma
    [p: p in PrimesUpTo(2*10^8) | forall{p+r: r in [6,8,14,18,20,24,26] | IsPrime(p+r)}]; // Vincenzo Librandi, Sep 30 2015
    
  • Mathematica
    Select[Prime[Range[200000]], Union[PrimeQ[# + {6, 8, 14, 18, 20, 24, 26}]] == {True} &] (* Vincenzo Librandi, Sep 30 2015 *)
    Select[Prime[Range[125*10^6]],AllTrue[#+{6,8,14,18,20,24,26},PrimeQ]&] (* Harvey P. Dale, Jul 21 2025 *)
  • PARI
    forprime(p=2, 1e30, if (isprime(p+6) && isprime(p+8) && isprime(p+14) && isprime(p+18) && isprime(p+20) && isprime(p+24) && isprime(p+26) , print1(p", "))) \\ Altug Alkan, Sep 30 2015
  • Perl
    use ntheory ":all"; say for sieve_prime_cluster(1,1e10, 6,8,14,18,20,24,26); # Dana Jacobsen, Sep 30 2015
    

Formula

a(n) = 210*A357890(n) + 173. - Hugo Pfoertner, Nov 18 2022

A357889 a(n) = (A022010(n) - 179)/210.

Original entry on oeis.org

26, 422, 1355, 2983, 4074, 5460, 31242, 35906, 40825, 84968, 90902, 114293, 204675, 207304, 329316, 353648, 377182, 382985, 400497, 418993, 590790, 611757, 686734, 748244, 993947, 1038255, 1181931, 1246060, 1310026, 1347976, 1354707, 1440679, 1477788, 1559980, 1720425, 1915719, 1989590
Offset: 1

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Author

Hugo Pfoertner, Nov 18 2022

Keywords

Comments

Linear conversion of the initial members of prime septuplets of second type.
Numbers k such that 210*k+179, 210*k+181, 210*k+187, 210*k+191, 210*k+193, 210*k+197, and 210*k+199 are all primes. - Jianing Song, Nov 18 2022

Crossrefs

Cf. A022009, A022010, A182387 (similar for prime septuplets of first type).
A357890 is a subsequence.
Showing 1-2 of 2 results.