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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A078850 Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[4,2,6]; short d-string notation of pattern = [426].

Original entry on oeis.org

67, 1447, 2377, 2707, 5437, 5737, 7207, 9337, 11827, 12037, 19207, 21487, 21517, 23197, 26107, 26947, 28657, 31147, 31177, 35797, 37357, 37567, 42697, 50587, 52177, 65167, 67927, 69997, 71707, 74197, 79147, 81547, 103087, 103387, 106657
Offset: 1

Views

Author

Labos Elemer, Dec 11 2002

Keywords

Comments

Subsequence of A022005. - R. J. Mathar, May 06 2017

Examples

			p=67,67+4=71,67+4+2=73,67+4+2+6=79 are consecutive primes.
		

Crossrefs

Cf. analogous prime quadruple sequences with various possible {2, 4, 6}-difference-patterns in brackets: A007530[242], A078847[246], A078848[264], A078849[266], A052378[424], A078850[426], A078851[462], A078852[466], A078853[624], A078854[626], A078855[642], A078856[646], A078857[662], A078858[664], A033451[666].

Programs

  • Mathematica
    d = {4, 2, 6}; First /@ Select[Partition[Prime@ Range@ 12000, Length@ d + 1, 1], Differences@ # == d &] (* Michael De Vlieger, May 02 2016 *)

Formula

Primes p = p(i) such that p(i+1)=p+4, p(i+2)=p+4+2, p(i+3)=p+4+2+6.

Extensions

Listed terms verified by Ray Chandler, Apr 20 2009

A078959 Primes p such that the differences between the 5 consecutive primes starting with p are (6,2,6,4).

Original entry on oeis.org

23, 53, 263, 1283, 2333, 5843, 6563, 14543, 19373, 32363, 41603, 48473, 49193, 51413, 75983, 88793, 106853, 113153, 115763, 138563, 150203, 160073, 163973, 204353, 223823, 229763, 246923, 284723, 319673, 326993, 337853, 338153, 357653, 433253, 443153, 460073, 460973
Offset: 1

Views

Author

Labos Elemer, Dec 19 2002

Keywords

Comments

Equivalently, primes p such that p, p+6, p+8, p+14 and p+18 are consecutive primes.

Examples

			53 is a term since 53, 59 = 53 + 6, 61 = 53 + 8, 67 = 53 + 14 and 71 = 53 + 18 are consecutive primes.
		

Crossrefs

Subsequence of A078854. - R. J. Mathar, May 06 2017

Programs

  • Mathematica
    l = {}; For[n = 1, n < 10^5, n++, If[Prime[n] + 6 == Prime[n + 1] \[And] Prime[n] + 8 == Prime[n + 2] \[And] Prime[n] + 14 == Prime[n + 3] \[And] Prime[n] + 18 == Prime[n + 4], AppendTo[l, Prime[n]]]]; l (* Jake Foster, Oct 27 2008 *)
    Select[Partition[Prime[Range[50000]], 5, 1], Differences[#] == {6,2,6,4} &][[;;, 1]] (* Amiram Eldar, Feb 22 2025 *)
  • PARI
    list(lim) = {my(p1 = 2, p2 = 3, p3 = 5, p4 = 7); forprime(p5 = 11, lim, if(p2 - p1 == 6 && p3 - p2 == 2 && p4 - p3 == 6 && p5 - p4 == 4, print1(p1, ", ")); p1 = p2; p2 = p3; p3 = p4; p4 = p5);} \\ Amiram Eldar, Feb 22 2025

Formula

a(n) == 23 (mod 30). - Amiram Eldar, Feb 22 2025

Extensions

Edited by Dean Hickerson, Dec 20 2002

A079017 Suppose p and q = p+14 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 15 possible difference patterns, namely [14], [2,12], [6,8], [8,6], [12,2], [2,4,8], [2,6,6], [2,10,2], [6,2,6], [6,6,2], [8,4,2], [2,4,6,2], [2,6,4,2], [2,2,4,2,4], [2,4,2,4,2]. Sequence gives smallest value of p for each difference pattern, sorted by magnitude.

Original entry on oeis.org

3, 5, 17, 23, 29, 47, 83, 89, 113, 137, 149, 197, 359, 509, 1997
Offset: 1

Views

Author

Labos Elemer, Jan 24 2003

Keywords

Examples

			p=1997, q=2011 has difference pattern [2,4,8] and {1997,1999,2003,2011} is the corresponding consecutive prime 4-tuple.
		

Crossrefs

A022006(1)=5, A022007(1)=7, A078847(1)=17, A078851(1)=19, A078946(1)=17, A078854(1)=23, A078948(1)=29, A078857(1)=47, A031932(1)=113, A078849(1)=149.

A078960 Primes p such that the differences between the 5 consecutive primes starting with p are (6,2,6,6).

Original entry on oeis.org

593, 4643, 6353, 11483, 19463, 34253, 71333, 77543, 89513, 101273, 135593, 148853, 179813, 184823, 191453, 193373, 245513, 260003, 267893, 277883, 280583, 302573, 307253, 308303, 310223, 344243, 346433, 350423, 376463, 408203, 416393, 435563, 442823, 450473, 482393
Offset: 1

Views

Author

Labos Elemer, Dec 19 2002

Keywords

Comments

Equivalently, primes p such that p, p+6, p+8, p+14 and p+20 are consecutive primes.

Examples

			593 is in the sequence since 593, 599 = 593 + 6, 601 = 593 + 8, 607 = 593 + 14 and 613 = 593 + 20 are consecutive primes.
		

Crossrefs

Subsequence of A078854. - R. J. Mathar, May 06 2017

Programs

  • Mathematica
    Transpose[Select[Partition[Prime[Range[36000]],5,1],Differences[#]=={6,2,6,6}&]][[1]] (* Harvey P. Dale, Oct 14 2013 *)
  • PARI
    list(lim) = {my(p1 = 2, p2 = 3, p3 = 5, p4 = 7); forprime(p5 = 11, lim, if(p2 - p1 == 6 && p3 - p2 == 2 && p4 - p3 == 6 && p5 - p4 == 6, print1(p1, ", ")); p1 = p2; p2 = p3; p3 = p4; p4 = p5);} \\ Amiram Eldar, Feb 22 2025

Formula

a(n) == 23 (mod 30). - Amiram Eldar, Feb 22 2025

Extensions

Edited by Dean Hickerson, Dec 20 2002

A258879 Numbers k such that k is the average of four consecutive primes k-7, k-1, k+1 and k+7.

Original entry on oeis.org

30, 60, 270, 570, 600, 1230, 1290, 1620, 2340, 2550, 3540, 4020, 4650, 5850, 6270, 6360, 6570, 10860, 11490, 14550, 15270, 17490, 19080, 19380, 19470, 23670, 26730, 29130, 32370, 34260, 41610, 48480, 49200, 49530, 51420, 51480
Offset: 1

Views

Author

Karl V. Keller, Jr., Jun 13 2015

Keywords

Comments

This sequence is a subsequence of A014574 (average of twin prime pairs), A256753 and A249674 (30*n).

Examples

			For k=30: 23, 29, 31, 37 are consecutive primes (k-7=23, k-1=29, k+1=31, k+7=37).
For k=60: 53, 59, 61, 67 are consecutive primes (k-7=53, k-1=59, k+1=61, k+7=67).
		

Crossrefs

Cf. A014574, A077800 (twin primes), A078854, A249674, A256753.

Programs

  • Magma
    [n: n in [13..2*10^5] | IsPrime(n-7) and IsPrime(n-1) and IsPrime(n+1) and IsPrime(n+7)]; // Vincenzo Librandi Jul 16 2015
    
  • Mathematica
    Select[ 5 Range@ 11000, PrimeQ[# - 7] && PrimeQ[# - 1] && PrimeQ[# + 1] && PrimeQ[# + 7] &] (* Robert G. Wilson v, Jun 28 2015 *)
  • PARI
    main(size)={my(v=vector(size),i,t=8);for(i=1,size,while(1,if(isprime(t-7)&&isprime(t-1)&&isprime(t+1)&&isprime(t+7),v[i]=t;break,t++));t++);return(v);} /* Anders Hellström, Jul 17 2015 */
  • Python
    from sympy import isprime, prevprime, nextprime
    for i in range(0, 10001, 2):
      if isprime(i-1) and isprime(i+1):
        if prevprime(i-1) == i-7 and nextprime(i+1) == i+7: print(i, end=', ')
    

Formula

a(n) = A078854(n) + 7.

A282059 Numbers k where there are 8 primes between 10*k and 10*k + 30.

Original entry on oeis.org

1, 8879, 28472, 85571, 114677, 656099, 1576009, 2565844, 6915653, 7426625, 9362599, 18240349, 21803372, 22644952, 26167277, 30254276, 66197230, 91093591, 96466961, 104209078, 107132278, 117022186, 134030186, 139402516, 140053322, 142247591, 145927027
Offset: 1

Views

Author

Wolfram Hüttermann, Feb 05 2017

Keywords

Comments

8 primes are the maximum in such an interval. Dickson's conjecture would indicate that there are infinitely many k. It is easy to prove that k = 21*m + r with r in {1, 17}.

Examples

			There are eight primes between 88790 and 88820: 88793, 88799, 88801, 88807, 88811, 88813, 88817, 88819. Therefore 8879 is in the sequence.
		

Crossrefs

Cf. A078854, A007530 (prime quadruplets).
For the Dickson conjecture see A020497.

Extensions

a(18)-a(27) from Giovanni Resta, Mar 29 2017
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