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.

A348024 a(n) = [x^n] Product_{k=1..2*n} (x + (-1)^k * k).

Original entry on oeis.org

1, 1, -13, -87, 2609, 34965, -1638841, -33411007, 2128380881, 58501278297, -4709853961605, -163166745402375, 15875893807564465, 664163782026582877, -75766955207796981345, -3716140360596415682175, 486265092408065178623265, 27363821966293458296896305, -4039473192629570940395992765
Offset: 0

Views

Author

Seiichi Manyama, Sep 25 2021

Keywords

Crossrefs

Programs

  • PARI
    a(n) = polcoef(prod(k=1, 2*n, x+(-1)^k*k), n);

Formula

a(n) = A047991(2*n,n).