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.

A007870 Determinant of character table of symmetric group S_n.

Original entry on oeis.org

1, 1, 2, 6, 96, 2880, 9953280, 100329062400, 10651768002183168000, 150283391703941024789299200000, 9263795272057860957392207640004657152000000000, 16027108137650009941734148595388542471170145479274004480000000000000
Offset: 0

Views

Author

Peter J. Cameron, Götz Pfeiffer [ goetz(AT)dcs.st-and.ac.uk ]

Keywords

Examples

			1 + x + 2*x^2 + 6*x^3 + 96*x^4 + 2880*x^5 + 9953280*x^6 + 100329062400*x^7 + ...
The integer partitions of 4 are {(4), (3,1), (2,2), (2,1,1), (1,1,1,1)} with product 4*3*1*2*2*2*1*1*1*1*1*1 = 96. - _Gus Wiseman_, May 09 2019
		

Crossrefs

Programs

  • GAP
    List(List([0..11],n->Flat(Partitions(n))),Product); # Muniru A Asiru, Dec 21 2018
    
  • Maple
    b:= proc(n, i) option remember; `if`(n=0 or i=1, [1$2], ((f, g)->
          [f[1]+g[1], f[2]*g[2]*i^g[1]])(b(n, i-1), b(n-i, min(n-i, i))))
        end:
    a:= n-> b(n$2)[2]:
    seq(a(n), n=0..12);  # Alois P. Heinz, Jul 30 2013
  • Mathematica
    Needs["Combinatorica`"]; Table[Times@@Flatten[Partitions[n]], {n, 10}]
    a[ n_] := If[n < 0, 0, Times @@ Flatten @ IntegerPartitions @ n] (* Michael Somos, Jun 11 2012 *)
    Table[Exp[Total[Map[Log, IntegerPartitions [n]], 2]], {n, 1, 25}] (* Richard R. Forberg, Dec 08 2014 *)
    b[n_, i_] := b[n, i] = If[n == 0, {1, 1}, Function[{f, g}, {f[[1]] + g[[1]], f[[2]]*g[[2]]*i^g[[1]]}][If[i < 2, {0, 1}, b[n, i - 1]], If[i > n, {0, 1}, b[n - i, i]]]]; a[n_] := b[n, n][[2]]; Table[a[n], {n, 0, 12}] (* Jean-François Alcover, Aug 29 2016, after Alois P. Heinz *)
  • Python
    from sympy import prod
    from sympy.utilities.iterables import ordered_partitions
    a = lambda n: prod(map(prod, ordered_partitions(n))) if n > 0 else 1
    print([a(n) for n in range(0, 12)]) # Darío Clavijo, Feb 22 2024

Formula

Product of all parts of all partitions of n.
From Gus Wiseman, May 09 2019: (Start)
a(n) = A003963(A325501(n)).
A001222(a(n)) = A325536(n).
A001221(a(n)) = A000720(n).
(End)