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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A201596 Record (maximal) gaps between prime triples (p, p+4, p+6).

Original entry on oeis.org

6, 24, 30, 90, 150, 156, 210, 240, 306, 366, 384, 444, 810, 834, 1086, 1200, 1326, 2316, 3876, 4230, 4350, 8244, 8880, 9450, 10686, 10950, 11784, 12816, 13554, 15504, 15576, 16254, 16506, 16596, 19446, 19944, 21516, 38340, 39990, 41556, 45786, 47190, 48246, 59856
Offset: 1

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Author

Alexei Kourbatov, Dec 03 2011

Keywords

Comments

Prime triples (p, p+4, p+6) are one of the two types of densest permissible constellations of 3 primes (A022004 and A022005). By the Hardy-Littlewood k-tuple conjecture, average gaps between prime k-tuples are O(log^k(p)), with k=3 for triples. If a gap is larger than any preceding gap, we call it a maximal gap, or a record gap. Maximal gaps may be significantly larger than average gaps; this sequence suggests that maximal gaps between triples are O(log^4(p)).
A201597 lists initial primes p in triples (p, p+4, p+6) preceding the maximal gaps. A233435 lists the corresponding primes p at the end of the maximal gaps.

Examples

			The gap of 6 between triples starting at p=7 and p=13 is the very first gap, so a(1)=6. The gap of 24 between triples starting at p=13 and p=37 is a maximal gap - larger than any preceding gap; therefore a(2)=24. The gap of 30 between triples at p=37 and p=67 is again a maximal gap, so a(3)=30. The next gap is smaller, so it does not contribute to the sequence.
		

Crossrefs

Programs

  • Mathematica
    DeleteDuplicates[Differences[Select[Partition[Prime[Range[5*10^6]],3,1],Differences[#]=={4,2}&][[;;,1]]],GreaterEqual]  (* Harvey P. Dale, Feb 26 2023 *)

Formula

Gaps between prime triples (p, p+4, p+6) are smaller than 0.35*(log p)^4, where p is the prime at the end of the gap. There is no rigorous proof of this formula. The O(log^4(p)) growth rate is suggested by numerical data and heuristics based on probability considerations.

A233435 Primes p in prime triples (p, p+4, p+6) at the end of the maximal gaps in A201596.

Original entry on oeis.org

13, 37, 67, 193, 457, 613, 823, 2377, 2683, 3163, 3847, 5227, 6547, 10267, 15643, 25303, 47143, 54493
Offset: 1

Views

Author

Alexei Kourbatov, Dec 09 2013

Keywords

Comments

Prime triples (p, p+4, p+6) are one of the two types of densest permissible constellations of 3 primes. Maximal gaps between triples of this type are listed in A201596; see more comments there.

Examples

			The gap of 6 between triples starting at p=7 and p=13 is the very first gap, so a(1)=13. The gap of 24 between triples starting at p=13 and p=37 is a maximal (record) gap - larger than any preceding gap; therefore a(2)=37. The gap of 30 between triples at p=37 and p=67 is again a record, so a(3)=67. The next gap is smaller, so a new term is not added to the sequence.
		

Crossrefs

Showing 1-2 of 2 results.