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

A382810 Primes p such that p + 6, p + 10 and p + 16 are also primes.

Original entry on oeis.org

7, 13, 31, 37, 73, 97, 157, 223, 373, 433, 1087, 1291, 1423, 1483, 1543, 1861, 1987, 2341, 2383, 2677, 2683, 3313, 3607, 4441, 4507, 4783, 4993, 5641, 5851, 6037, 6961, 7237, 7867, 8731, 9613, 9733, 10723, 13093, 13681, 14143, 14731, 16057, 16411, 16921, 17377
Offset: 1

Views

Author

Alexander Yutkin, Apr 05 2025

Keywords

Comments

The four primes need not be consecutive; otherwise we have the sequence A078856.

Examples

			p=37: 37+6=43, 37+10=47, 37+16=53 -> prime quartet: (37, 43, 47, 53).
		

Crossrefs

Cf. A078852 [4, 6, 6], A078856 [6, 4, 6], A078858 [6, 6, 4], A033451 [6, 6, 6].

Programs

  • Maple
    q:= p-> andmap(i->isprime(p+i), [0, 6, 10, 16]):
    select(q, [$2..20000])[];  # Alois P. Heinz, Apr 05 2025
  • Mathematica
    Select[Prime[Range[2000]],AllTrue[#+{6,10,16},PrimeQ]&] (* James C. McMahon, Apr 13 2025 *)

A078869 Number of n-tuples with elements in {2,4,6} which can occur as the differences between n+1 consecutive primes > n+1. (Values of a(11), ..., a(18) are conjectured to be correct, but are only known to be upper bounds.)

Original entry on oeis.org

3, 7, 15, 26, 38, 48, 67, 92, 105, 108, 109, 118, 130, 128, 112, 80, 36, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
Offset: 1

Views

Author

Labos Elemer, Dec 19 2002

Keywords

Comments

The ">n+1" rules out n-tuples like (2,2), which only occurs for the primes 3, 5, 7. All terms from a(19) on equal 0.
An n-tuple (a_1,a_2,...,a_n) is counted iff the partial sums 0, a_1, a_1+a_2, ..., a_1+...+a_n do not contain a complete residue system (mod p) for any prime p.

Crossrefs

The 26 4-tuples and 38 5-tuples are in A078868 and A078870. Cf. A001359, A008407, A029710, A031924, A022004-A022007, A078852, A078858, A078946-A078969, A020497.

Programs

  • Mathematica
    test[tuple_] := Module[{r, sums, i, j}, r=Length[tuple]; sums=Prepend[tuple.Table[If[j>=i, 1, 0], {i, 1, r}, {j, 1, r}], 0]; For[i=1, Prime[i]<=r+1, i++, If[Length[Union[Mod[sums, Prime[i]]]]==Prime[i], Return[False]]]; True]; tuples[0]={{}}; tuples[n_] := tuples[n]=Select[Flatten[Outer[Append, tuples[n-1], {2, 4, 6}, 1], 1], test]; a[n_] := Length[tuples[n]]

Extensions

Edited by Dean Hickerson, Dec 20 2002

A078966 Primes p such that the differences between the 5 consecutive primes starting with p are (6,6,4,2).

Original entry on oeis.org

601, 2671, 20341, 24091, 41941, 42391, 55201, 65701, 87541, 125101, 198811, 249421, 355501, 414691, 416401, 428551, 510061, 521161, 541531, 543871, 560221, 603901, 609601, 637711, 663961, 669661, 743161, 770041, 986131, 1020961, 1026661, 1099711, 1113181, 1120501
Offset: 1

Views

Author

Labos Elemer, Dec 19 2002

Keywords

Comments

Equivalently, primes p such that p, p+6, p+12, p+16 and p+18 are consecutive primes.

Examples

			601 is in the sequence since 601, 607 = 601 + 6, 613 = 601 + 12, 617 = 601 + 16 and 619 = 601 + 18 are consecutive primes.
		

Crossrefs

Subsequence of A078858. - R. J. Mathar, May 06 2017

Programs

  • Mathematica
    Transpose[Select[Partition[Prime[Range[81000]],5,1],Differences[#] == {6,6,4,2}&]][[1]] (* Harvey P. Dale, Sep 15 2011 *)
  • PARI
    list(lim) = {my(p1 = 2, p2 = 3, p3 = 5, p4 = 7); forprime(p5 = 11, lim, if(p2 - p1 == 6 && p3 - p2 == 6 && p4 - p3 == 4 && p5 - p4 == 2, print1(p1, ", ")); p1 = p2; p2 = p3; p3 = p4; p4 = p5);} \\ Amiram Eldar, Feb 22 2025

Formula

a(n) == 1 (mod 30). - Amiram Eldar, Feb 22 2025

Extensions

Edited by Dean Hickerson, Dec 20 2002

A078967 Primes p such that the differences between the 5 consecutive primes starting with p are (6,6,4,6).

Original entry on oeis.org

151, 367, 3307, 4987, 20101, 30097, 52951, 53617, 85831, 92221, 95701, 99817, 103561, 128461, 135601, 163621, 214651, 221071, 241321, 241861, 246907, 274831, 280591, 282691, 287851, 294787, 295831, 297601, 307261, 308311, 334771, 340897, 347161, 350431, 354301
Offset: 1

Views

Author

Labos Elemer, Dec 19 2002

Keywords

Comments

Equivalently, primes p such that p, p+6, p+12, p+16 and p+22 are consecutive primes.

Examples

			151 is in the sequence since 151, 157 = 151 + 6, 163 = 151 + 12, 167 = 151 + 16 and 173 = 151 + 22 are consecutive primes.
		

Crossrefs

Subsequence of A078858. - R. J. Mathar, May 06 2017

Programs

  • Mathematica
    Transpose[Select[Partition[Prime[Range[30000]],5,1],Differences[#] == {6,6,4,6}&]][[1]] (* Harvey P. Dale, Apr 06 2012 *)
  • PARI
    list(lim) = {my(p1 = 2, p2 = 3, p3 = 5, p4 = 7); forprime(p5 = 11, lim, if(p2 - p1 == 6 && p3 - p2 == 6 && p4 - p3 == 4 && p5 - p4 == 6, print1(p1, ", ")); p1 = p2; p2 = p3; p3 = p4; p4 = p5);} \\ Amiram Eldar, Feb 22 2025

Formula

From Amiram Eldar, Feb 22 2025: (Start)
a(n) == 1 (mod 6).
a(n) == 1 or 7 (mod 30). (End)

Extensions

Edited by Dean Hickerson, Dec 20 2002

A079018 Suppose p and q = p+16 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 17 possible difference patterns, namely [16], [4,12], [6,10], [10,6], [12,4], [4,2,10], [4,6,6], [4,8,4], [6,4,6], [6,6,4], [10,2,4], [4,2,4,6], [4,2,6,4], [4,6,2,4], [6,4,2,4], [4,2,4,2,4], [2,2,4,2,4,2]. Sequence gives smallest value of p for each difference pattern, sorted by magnitude.

Original entry on oeis.org

3, 7, 13, 31, 43, 67, 73, 151, 181, 211, 241, 277, 331, 463, 487, 1597, 1831
Offset: 1

Views

Author

Labos Elemer, Jan 24 2003

Keywords

Examples

			p=181, q=197 has difference pattern [10,2,4] and {181,191,193,197} is the corresponding consecutive prime 4-tuple.
		

Crossrefs

A022008(1)=7, A078952(1)=13, A078852(1)=73, A078953(1)=67, A078954(1)=1597, A078961(1)=31, A078856(1)=73, A078858(1)=151, A031934(1)=A000230(8)=1831.

A215719 The smallest of four consecutive primes with prime gaps {a,b,c} = {10,18,2}.

Original entry on oeis.org

1249, 14293, 17929, 31741, 32089, 33151, 35869, 57193, 60859, 64891, 71443, 85303, 87481, 90793, 93103, 98533, 99679, 99961, 108079, 131221, 135319, 139429, 140731, 144451, 157639, 165559, 171439, 175909, 180043, 186619, 193153, 203353, 214531, 217489
Offset: 1

Views

Author

V.J. Pohjola, Aug 22 2012

Keywords

Comments

Conjecture: The terms of any feasible prime gap triple {a,b,c} to form a quadruple of consecutive primes are sums of terms of three consecutive subsequences of the infinite integer sequence with period (4,2,4,2,4,6,2,6). By this token all possible sequences of quadruples of consecutive primes can be generated, including those already in the OEIS.

Examples

			The terms of the prime gap triple {10,18,2} are the sums of the terms of the following (arbitrarily chosen) subsequences ..., {4,2,4}, {6,2,6,4}, {2}, ... For n=3, a(n) = 17929 is the smallest prime of the third prime quadruple {17929, 17939, 17957, 17959}.
		

Crossrefs

Cf. A078858.

Programs

  • Maple
    N:= 10^6; # to get all terms <= 6*N
    Primes1:= select(isprime,{seq(6*i+1,i=1..N+5)}):
    Primes5:= select(isprime,{seq(6*i+5,i=1..N+5)}):
    Q:= `intersect`(Primes1, map(t->t-10, Primes5), map(t->t-28,Primes5), map(t->t-30,Primes1):
    A215719:= select(t -> select(isprime,{seq(t+2*i,i=1..13)}) = {t+10}, Q): # Robert Israel, May 04 2014

Extensions

Definition and comment corrected by Robert Israel, May 04 2014
Previous Showing 11-17 of 17 results.