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.

A361823 a(1) = 3; thereafter, a(n+1) is the smallest prime p such that p - prevprime(p) >= a(n) - prevprime(a(n)).

Original entry on oeis.org

3, 5, 7, 11, 17, 23, 29, 37, 53, 59, 67, 79, 89, 97, 127, 307, 331, 541, 907, 1151, 1361, 8501, 9587, 12889, 14143, 15727, 19661, 25523, 31469, 156007, 338119, 360749, 370373, 492227, 1349651, 1357333, 1562051, 2010881, 4652507, 11114087, 15204131, 17051887
Offset: 1

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Author

Ya-Ping Lu, Mar 25 2023

Keywords

Comments

a(n) is the leading prime in the (n+1)-th prime sublist defined in A348178.

Crossrefs

Programs

  • PARI
    a361823(upto) = {my(pp=2, gap=1); forprime (p=3, upto, my(g=p-pp);if(g>=gap, print1(p,", "); gap=g); pp=p)};
    a361823(20000000) \\ Hugo Pfoertner, Apr 03 2023
  • Python
    from sympy import nextprime; q = 2; g = 0
    while q < 20000000:
        p = nextprime(q); d = p - q
        if d >= g: print(p, end = ', '); g = d
        q = p
    

Formula

a(n) = nextprime(A134266(n)). - Michel Marcus, Mar 30 2023