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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A078946 Primes p such that p, p+2, p+6, p+12 and p+14 are consecutive primes.

Original entry on oeis.org

17, 227, 1277, 1607, 3527, 3917, 4637, 4787, 27737, 38447, 39227, 44267, 71327, 97367, 99707, 113147, 122027, 122387, 124337, 165707, 183497, 187127, 191447, 197957, 198827, 275447, 290657, 312197, 317957, 347057, 349397, 416387, 418337, 421697, 427067, 443867
Offset: 1

Views

Author

Labos Elemer, Dec 19 2002

Keywords

Examples

			227 is in the sequence since 227, 229 = 227 + 2, 233 = 227 + 6, 239 = 227 + 12 and 241 = 227 + 14 are consecutive primes.
		

Crossrefs

Subsequence of A128468.
Subsequence of A078847. - R. J. Mathar, Feb 10 2013

Programs

  • Magma
    [p: p in PrimesInInterval(7,1000000) | forall{i: i in [2,6,12,14] | IsPrime(p+i)}]; // Vincenzo Librandi, Apr 19 2015
  • Mathematica
    Rest@ Select[Prime@ Range@ 36000, AllTrue[{2, 6, 12, 14} + #, PrimeQ] &] (* Michael De Vlieger, Apr 18 2015, Version 10 *)
    Select[Partition[Prime[Range[36000]],5,1],Differences[#]=={2,4,6,2}&][[All,1]] (* Harvey P. Dale, Jun 14 2022 *)
  • PARI
    isok(p) = isprime(p) && (nextprime(p+1)==p+2) && (nextprime(p+3)== p+6) && (nextprime(p+7)==p+12) && (nextprime(p+13)==p+14); \\ Michel Marcus, Dec 10 2013
    
  • PARI
    list(lim) = {my(p1 = 2, p2 = 3, p3 = 5, p4 = 7); forprime(p5 = 11, lim, if(p2 - p1 == 2 && p3 - p2 == 4 && p4 - p3 == 6 && p5 - p4 == 2, print1(p1, ", ")); p1 = p2; p2 = p3; p3 = p4; p4 = p5);} \\ Amiram Eldar, Feb 21 2025
    

Formula

a(n) == 17 (mod 30). - Amiram Eldar, Feb 21 2025

Extensions

Edited by Dean Hickerson, Dec 20 2002

A079019 Suppose p and q = p+18 are primes. Define the difference pattern of (p,q) to be the successive differences of the primes in the range p to q. There are 49 possible difference patterns, shown in the Comments line. Sequence gives smallest value of p for each difference pattern, sorted by magnitude.

Original entry on oeis.org

5, 11, 13, 19, 23, 29, 41, 43, 61, 71, 79, 83, 89, 109, 113, 131, 139, 149, 179, 181, 193, 211, 239, 251, 331, 401, 461, 491, 503, 523, 569, 601, 659, 691, 733, 739, 743, 821, 1303, 1531, 1601, 1861, 1931, 1933, 1993, 2069, 3313, 4201, 18043
Offset: 1

Views

Author

Labos Elemer, Jan 24 2003

Keywords

Comments

Difference patterns are [18], [2,16], [4,14], [6,12], [8,10], [10,8], [12,6], [14,4], [16,2], [2,4,12], [2,6,10], [2,10,6], [2,12,4], [4,2,12], [4,6,8], [4,8,6], [4,12,2], [6,2,10], [6,4,8], [6,6,6], [6,8,4], [6,10,2], [8,4,6], [8,6,4], [10,2,6], [10,6,2], [12,2,4], [12,4,2], [2,4,2,10], [2,4,6,6], [2,6,4,6], [2,6,6,4], [2,10,2,4], [4,2,4,8], [4,2,10,2], [4,6,2,6], [4,6,6,2], [6,2,4,6], [6,2,6,4], [6,4,2,6], [6,4,6,2], [6,6,4,2], [8,4,2,4], [10,2,4,2], [2,4,2,4,6], [2,6,4,2,4], [4,2,4,6,2], [6,4,2,4,2], [2,4,2,4,2,4].

Examples

			p=18043, q=18061 has difference pattern [4,2,10,2] and {18043,18047,18049,18059,18061} is the corresponding consecutive prime 5-tuple.
		

Crossrefs

A078947[1]=41, A078949[1]=71, A078950[1]=149, A078955[1]=19, A078956[1]=43, A078959[1]=23, A078962[1]=61, A078966[1]=601, A078958[1]=1601, A078963[1]=3313, A031936[1]=A000230[9]=523.

Extensions

Corrected by Rick L. Shepherd, Aug 30 2003
Showing 1-2 of 2 results.