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.

A268963 Primes 4k+1 at the end of the maximal gaps in A084162.

Original entry on oeis.org

5, 13, 29, 89, 137, 229, 509, 1549, 1861, 9601, 15733, 16829, 33289, 39709, 50741, 180949, 183289, 1562053, 1638053, 2244157, 4469141, 4874977, 7856713, 10087481, 12021353, 12214273, 18227081, 148364081, 292182557, 320262769, 468214457, 727335397, 869766761
Offset: 0

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Author

Alexei Kourbatov, Feb 16 2016

Keywords

Comments

Subsequence of A002144.
A084161 lists the primes preceding the maximal gaps, and A084162 lists the corresponding gap sizes. See more comments there.

Examples

			a(3) = 89: There are no primes p = 1 mod 4 between 73 and 89, this gap is the largest up to 89, the gap size is 16.
		

Crossrefs

Programs

  • Mathematica
    Reap[Print[5]; Sow[5]; r = 0; p = 5; For[q = 7, q < 10^7, q = NextPrime[q], If[Mod[q, 4] == 3, Continue[]]; g = q - p; If[g > r, r = g; Print[q] Sow[q]]; p = q]][[2, 1]] (* Jean-François Alcover, Feb 20 2019, from PARI *)
  • PARI
    print1(5); r=0; p=5; forprime(q=7, 1e9, if(q%4==3, next); g=q-p; if(g>r, r=g; print1(", "q)); p=q)

Formula

a(n) = A084161(n) + A084162(n)