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.

A375250 a(n) = A375251(n) / A010790(n) = denominator(W1([n], x)) / (n!*(n - 1)!), where W1([n], x) is the first Sylvester wave for parts in [n].

Original entry on oeis.org

1, 2, 6, 2, 30, 12, 42, 6, 30, 20, 44, 12, 910, 420, 30, 6, 102, 12, 7980, 420, 13860, 1320, 4140, 180, 2730, 1092, 84, 28, 58, 60, 2046, 66, 117810, 7140, 420, 12, 36556, 9880, 780, 20, 189420, 9240, 397320, 9240, 48300, 19320, 19740, 1260, 46410, 39780, 87516, 1716, 6996, 264
Offset: 1

Views

Author

Peter Luschny, Aug 09 2024

Keywords

Crossrefs

Programs

  • Maple
    read(PARTITIONS):  # From the paper of Sills & Zeilberger cited in A375252.
    a := n -> denom(op(pmnPC(n, x)[1])) / (n!*(n - 1)!):
    seq(a(n), n = 1..54);
    # Or, standalone:
    W := proc(n) local k; exp(t*x)/mul(1 - exp(-t*k), k=1..n);
    expand(series(%, t, n+1)); coeff(%, t, -1) end:
    a := n -> n*denom(W(n))/(n!^2): seq(a(n), n = 1..24);

Formula

a(n) = denominator(W(n))/(n!*(n - 1)!) where W(n) = [t^(-1)] exp(t*x)/ Product_{k=1..n}(1 - exp(-t*k)).