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.

A372240 a(n) = Product_{j=1..n} j^(floor(sqrt(j))).

Original entry on oeis.org

1, 1, 2, 6, 96, 2400, 86400, 4233600, 270950400, 197522841600, 197522841600000, 262902902169600000, 454296214949068800000, 998088784243104153600000, 2738755623963077797478400000, 9243300230875387566489600000000, 605768923930649399557462425600000000
Offset: 0

Views

Author

Vaclav Kotesovec, Apr 23 2024

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Product[j^(Floor[Sqrt[j]]), {j, 1, n}], {n, 0, 17}]

Formula

a(n^2) = A372241(n^2) * n!^2 / (n^2)!.
a(n^2) = (n^2)!^n * n!^2 / A255322(n).
log(a(n)) ~ (2*n^(3/2)/3 - n/2 - 5*sqrt(n)/6 + 1/4)*log(n) - 4*n^(3/2)/9 + n/2 - sqrt(n).