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.

A370830 Primes p such that the polynomial x^4-x^3-x^2-x-1 is irreducible mod p.

Original entry on oeis.org

2, 5, 31, 43, 53, 79, 83, 89, 97, 109, 131, 139, 151, 199, 229, 233, 239, 283, 313, 317, 359, 367, 389, 433, 443, 479, 487, 569, 571, 577, 601, 617, 641, 643, 659, 677, 769, 797, 823, 853, 857, 929, 937, 941, 971, 1013, 1019, 1049, 1063, 1069, 1087, 1093, 1117, 1163, 1171, 1181, 1231, 1249, 1283
Offset: 1

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Author

Robert Israel, Mar 13 2024

Keywords

Crossrefs

Subsequence of A106283. Cf. 106309.

Programs

  • Maple
    P:= x^4 - x^3 - x^2 - x - 1:
    select(p -> Irreduc(P) mod p, [seq(ithprime(i),i=1..1000)]);
  • Python
    from itertools import islice
    from sympy import Poly, nextprime
    from sympy.abc import x
    def A370830_gen(): # generator of terms
        p = 2
        while True:
            if Poly(x*(x*(x*(x-1)-1)-1)-1, x, modulus=p).is_irreducible:
                yield p
            p = nextprime(p)
    A370830_list = list(islice(A370830_gen(),20)) # Chai Wah Wu, Mar 14 2024