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 1-4 of 4 results.

A347849 Primes at lower end of record gaps between prime octuplets given by A347848.

Original entry on oeis.org

11, 25658441, 93625991, 226449521, 2843348351, 4090833821, 13421076281, 18856092371, 26092031081, 54270148391, 66449431661, 111422173391, 124168028051, 280837571081, 875319936761, 1247050623431, 3589081520021, 6363702282011, 7479508339601, 10804857261041, 15199582184861
Offset: 1

Views

Author

Hugo Pfoertner and Norman Luhn, Sep 16 2021

Keywords

Examples

			See A347848.
		

Crossrefs

Formula

a(n) == 11 (mod 210).

A022011 Initial members of prime octuplets (p, p+2, p+6, p+8, p+12, p+18, p+20, p+26).

Original entry on oeis.org

11, 15760091, 25658441, 93625991, 182403491, 226449521, 661972301, 910935911, 1042090781, 1071322781, 1170221861, 1394025161, 1459270271, 1712750771, 1742638811, 1935587651, 2048038451, 2397437501, 2799645461
Offset: 1

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Author

Keywords

Comments

All terms are congruent to 11 (modulo 210). - Matt C. Anderson, May 26 2015

References

  • Martin Gardner, The Last Recreations, Chapter 12: Strong Laws of Small Primes, Springer-Verlag, 1997, pp. 191-205, especially p. 197.
  • Martin Gardner, Patterns in primes are a clue to the strong law of small numbers, Mathematical Games column, Scientific American, (December, 1980), pp. 20ff.

Crossrefs

A065706 is the union of A022011, A022012 and A022013.
A346996(n) = a(10^n).

Programs

  • Magma
    [p: p in PrimesUpTo(4*10^8) | forall{p+r: r in [2,6,8,12,18,20,26] | IsPrime(p+r)}]; // Vincenzo Librandi, Oct 01 2015
    
  • Mathematica
    Select[Prime[Range[2 10^9]], Union[PrimeQ[# + {2, 6, 8, 12, 18, 20, 26}]] == {True} &] (* Vincenzo Librandi, Oct 01 2015 *)
  • PARI
    forprime(p=2, 10^30, if (isprime(p+2) && isprime(p+6) && isprime(p+8) && isprime(p+12) && isprime(p+18) && isprime(p+20) && isprime(p+26), print1(p", "))) \\ Altug Alkan, Oct 01 2015
  • Perl
    use ntheory ":all"; say for sieve_prime_cluster(1,1e10, 2,6,8,12,18,20,26); # Dana Jacobsen, Sep 30 2015
    

Extensions

Reference provided by Harvey P. Dale, May 10 2013
More terms from Matt C. Anderson, Dec 06 2013

A347850 Record gaps between prime octuplets of the form p + {0, 2, 6, 12, 14, 20, 24, 26} (initial members are A022012), divided by 30.

Original entry on oeis.org

42, 3729, 82250, 605241, 1249017, 1734985, 1747606, 3550360, 9578800, 10562911, 12208504, 24101070, 26510262, 38121281, 38588851, 47884158, 50246371, 56392908, 59827439, 66233760, 114058040, 120197366, 141646351, 141808504, 153247005, 168751151, 235079194, 244505074
Offset: 1

Views

Author

Hugo Pfoertner and Norman Luhn, Sep 16 2021

Keywords

Examples

			a(1) = (A022012(2) - A022012(1))/30 = (1277 - 17)/30 = 42; 17 = A347851(1).
a(5) = (A022012(13) - A022012(12))/30 = (171958667 - 165531257)/30 = 214247, exceeding all previous differences; 1655531257 = A347851(5).
		

Crossrefs

The primes at the lower end of the record gaps are given in A347851.

A347852 Record gaps between prime octuplets of the form p + {0, 6, 8, 14, 18, 20, 24, 26} (initial members are A022013), divided by 210.

Original entry on oeis.org

933, 2719, 25782, 298074, 684607, 3152985, 3615775, 4062023, 9213717, 17131290, 18003995, 19350016, 23725387, 30570595, 34125949, 39157518, 61083539, 67660632, 83438975, 94515652, 117202015, 119103567, 126310893, 127678285, 144003855, 189879059, 197614054, 240073574
Offset: 1

Views

Author

Hugo Pfoertner and Norman Luhn, Sep 16 2021

Keywords

Examples

			a(1) = (A022013(2) - A022013(1))/210 = (284723 - 88793)/210 = 933; 88793 = A347853(1).
a(6) = (A022013(11) - A022013(10))/210 = (964669613 - 302542763)/210 = 3152985, exceeding all previous differences; 302542763 = A347853(6).
		

Crossrefs

The primes at the lower end of the record gaps are given in A347853.
Showing 1-4 of 4 results.