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.

A356271 Prime numbers in the sublists defined in A348168 that contain a single prime.

Original entry on oeis.org

2, 3, 5, 7, 23, 53, 89, 157, 173, 211, 293, 353, 359, 409, 449, 683, 691, 839, 919, 977, 983, 1039, 1069, 1103, 1109, 1201, 1223, 1237, 1283, 1327, 1381, 1439, 1459, 1511, 1613, 1627, 1637, 1709, 2039, 2099, 2179, 2213, 2221, 2243, 2251, 2273, 2447, 2633, 2917
Offset: 1

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Author

Ya-Ping Lu, Aug 01 2022

Keywords

Comments

It seems that lim_{n->oo} n/primepi(a(n)) = 0.102 approximately.

Crossrefs

Cf. A348168.

Programs

  • Python
    from sympy import nextprime; R = [2]; p0 = 2
    while len(R) < 50:
        p1 = nextprime(p0); p = nextprime(p1); g1 = p - p1
        if g1 >= p1 - p0: R.append(p1)
        else:
            while p - p1 <= g1: p1 = p; p = nextprime(p)
        p0 = p1
    print(*R, sep = ', ')