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.

A354691 Numbers k with the property that 4*p+q and 4*q+p are primes, where p = prime(k) and q = prime(k+1).

Original entry on oeis.org

2, 23, 74, 86, 91, 96, 97, 99, 100, 105, 133, 174, 280, 305, 357, 372, 504, 554, 562, 565, 660, 668, 686, 716, 733, 741, 789, 796, 859, 885, 909, 925, 993, 1021, 1103, 1131, 1136, 1144, 1191, 1215, 1234, 1248, 1285, 1326, 1334, 1414, 1503, 1559, 1577, 1590, 1607, 1656, 1738, 1751, 1822, 1847, 1894, 1929, 2088, 2090
Offset: 1

Views

Author

Zak Seidov, Jun 03 2022

Keywords

Programs

  • Mathematica
    sp = {}; sq = {}; Do[p = Prime[k]; q = NextPrime[p];
      If[PrimeQ[4*p + q], AppendTo[sp, k]];
      If[PrimeQ[4*q + p], AppendTo[sq, k]], {k, 10000}]; Intersection[sp, sq]
  • Python
    from itertools import islice
    from sympy import isprime, nextprime
    def agen(): # generator of terms
        k, p, q = 1, 2, 3
        while True:
            if isprime(4*p+q) and isprime(4*q+p):
                yield k
            k, p, q = k+1, q, nextprime(q)
    print(list(islice(agen(), 60))) # Michael S. Branicky, Jun 03 2022