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.

A367843 Maximum of the absolute value of the coefficients of (1 - x^2) * (1 - x^3) * (1 - x^5) * ... * (1 - x^prime(n)).

Original entry on oeis.org

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 3, 3, 4, 6, 8, 12, 18, 30, 46, 70, 113, 186, 314, 531, 894, 1561, 2705, 4817, 8514, 15030, 26502, 47200, 84698, 151809, 273961, 496807, 900596, 1643185, 2999837, 5498916, 10111429, 18596096, 34306158, 63585519, 118215700
Offset: 0

Views

Author

Ilya Gutkovskiy, Feb 06 2024

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Max[Abs[CoefficientList[Product[(1 - x^Prime[k]), {k, 1, n}], x]]], {n, 0, 46}]
  • Python
    from collections import Counter
    from sympy import prime
    def A367843(n):
        c = {0:1}
        for k in range(1,n+1):
            p, b = prime(k), Counter(c)
            for j in c:
                b[j+p] -= c[j]
            c = b
        return max(map(abs,c.values())) # Chai Wah Wu, Feb 06 2024