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.

Previous Showing 11-13 of 13 results.

A086644 Permanent of the character table of the symmetric group S_n.

Original entry on oeis.org

1, 0, 0, 0, 0, 0, 0, -20834715303936, 602706855887546351616
Offset: 1

Views

Author

Yuval Dekel (dekelyuval(AT)hotmail.com), Jul 26 2003

Keywords

Comments

In the Schmidt-Simion reference it is proved that if A000701(n) is odd then a(n) = 0. So a(11)=a(12)=a(13)=0. The computation of a(10) involves a permanent of dimension 42, and it may take a long time for GAP to compute it.

Crossrefs

Cf. A007870.

Programs

  • GAP
    Permanent(Irr(SymmetricGroup(n)));

Extensions

a(9) from Ferenc Szollosi, Jul 25 2014

A325536 Sum of sums of omegas of parts over all integer partitions of n.

Original entry on oeis.org

0, 0, 1, 2, 6, 9, 19, 28, 51, 75, 119, 170, 261, 362, 525, 723, 1019, 1373, 1890, 2512, 3386, 4452, 5893, 7658, 10017, 12881, 16627, 21210, 27097, 34266, 43392, 54462, 68399, 85285, 106305, 131712, 163132, 200936, 247332, 303066, 370989, 452296, 550875, 668495
Offset: 0

Views

Author

Gus Wiseman, May 08 2019

Keywords

Comments

Also omega of the product of products of parts over all integer partitions of n.
The omega of n is A001222(n), the number of prime factors of n counted with multiplicity.

Examples

			The integer partitions of 5 are {(5), (4,1), (3,2), (3,1,1), (2,2,1), (2,1,1,1), (1,1,1,1,1)} with products {5,4,6,3,4,2,1} with product 2880 with omega 9, so a(5) = 9.
		

Crossrefs

Programs

  • Mathematica
    Table[Plus@@PrimeOmega/@Join@@IntegerPartitions[n],{n,0,30}]

Formula

a(n) = A001222(A007870(n)).

A346788 Product over all partitions lambda of n of the product of distinct parts in lambda.

Original entry on oeis.org

1, 1, 2, 6, 48, 1440, 414720, 2090188800, 1155790798848000, 226483217146419609600000, 302971317675145105975227187200000000, 37917003542135076706761224377027811868672000000000000, 45800346382799680410294841758069930049013501333211737122406400000000000000000
Offset: 0

Views

Author

Alois P. Heinz, Aug 03 2021

Keywords

Crossrefs

Programs

  • Maple
    a:= n-> mul(i, i=map(x-> {x[]}[], combinat[partition](n))):
    seq(a(n), n=0..12);
  • Mathematica
    a[n_] := Times @@ Times @@@ Union /@ IntegerPartitions[n];
    a /@ Range[0, 20] (* Jean-François Alcover, Aug 09 2021 *)
  • PARI
    a(n) = vecprod(apply(x->vecprod(Set(x)), partitions(n))); \\ Michel Marcus, Aug 04 2021

Formula

a(n) = A230053(n) for n <= 6.
Previous Showing 11-13 of 13 results.