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.

A201597 Initial prime in prime triples (p, p+4, p+6) preceding the maximal gaps in A201596.

Original entry on oeis.org

7, 13, 37, 103, 307, 457, 613, 2137, 2377, 2797, 3463, 4783, 5737, 9433, 14557, 24103, 45817, 52177, 126487, 317587, 580687, 715873, 2719663, 6227563, 8114857, 10085623, 10137493, 18773137, 21297553, 25291363, 43472497, 52645423, 69718147, 80002627, 89776327
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. 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)=7. 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)=13. The gap of 30 between triples at p=37 and p=67 is again a maximal gap, so a(3)=37. The next gap is smaller, so it does not contribute to the sequence.
		

Crossrefs

Cf. A022005 (prime triples p, p+4, p+6), A201596.

Programs

  • Mathematica
    DeleteDuplicates[{#[[1]],#[[2]]-#[[1]]}&/@Partition[Select[Prime[Range[ 5206000]],AllTrue[#+{4,6},PrimeQ]&],2,1],GreaterEqual[#1[[2]],#2[[2]]]&] [[All,1]] (* Harvey P. Dale, Aug 04 2022 *)