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.

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A375694 Number A(n,k) of multiset permutations of {{1}^k, {2}^k, ..., {n}^k} with no fixed k-tuple {j}^k; square array A(n,k), n>=0, k>=0, read by antidiagonals.

Original entry on oeis.org

1, 1, 0, 1, 0, 0, 1, 0, 1, 0, 1, 0, 5, 2, 0, 1, 0, 19, 74, 9, 0, 1, 0, 69, 1622, 2193, 44, 0, 1, 0, 251, 34442, 362997, 101644, 265, 0, 1, 0, 923, 756002, 62924817, 166336604, 6840085, 1854, 0, 1, 0, 3431, 17150366, 11729719509, 305225265804, 136221590695, 630985830, 14833, 0
Offset: 0

Views

Author

Alois P. Heinz, Aug 24 2024

Keywords

Examples

			A(2,2) = 5: 1212, 1221, 2112, 2121, 2211.
A(2,3) = 19: 112122, 112212, 112221, 121122, 121212, 121221, 122112, 122121, 122211, 211122, 211212, 211221, 212112, 212121, 212211, 221112, 221121, 221211, 222111.
A(3,2) = 74: 121323, 121332, 122313, 122331, 123123, 123132, 123213, 123231, 123312, 123321, 131223, 131232, 131322, 132123, 132132, 132312, 132321, 133122, 133212, 133221, 211323, 211332, 212313, 212331, 213123, 213132, 213213, 213231, 213312, 213321, 221313, 221331, 223113, 223131, 223311, 231123, 231132, 231213, 231231, 231312, 231321, 232113, 232131, 232311, 233112, 233121, 233211, 311223, 311232, 311322, 312123, 312132, 312312, 312321, 313122, 313212, 313221, 321123, 321132, 321213, 321231, 321312, 321321, 322113, 322131, 322311, 323112, 323121, 323211, 331122, 331212, 331221, 332112, 332121.
A(4,1) = 9: 2143, 2341, 2413, 3142, 3412, 3421, 4123, 4312, 4321.
Square array A(n,k) begins:
  1,  1,      1,         1,            1,               1, ...
  0,  0,      0,         0,            0,               0, ...
  0,  1,      5,        19,           69,             251, ...
  0,  2,     74,      1622,        34442,          756002, ...
  0,  9,   2193,    362997,     62924817,     11729719509, ...
  0, 44, 101644, 166336604, 305225265804, 623302086965044, ...
		

Crossrefs

Columns k=0-2 give: A000007, A000166, A374980.
Rows n=0-2 give: A000012, A000004, A030662.
Main diagonal gives A375693.

Programs

  • Maple
    A:= (n, k)-> add((-1)^(n-j)*binomial(n, j)*(k*j)!/k!^j, j=0..n):
    seq(seq(A(n, d-n), n=0..d), d=0..10);

Formula

A(n,k) = Sum_{j=0..n} (-1)^(n-j)*binomial(n,j)*(k*j)!/k!^j.

A375778 Number of multiset permutations of {{1}^n, {2}^n, ..., {n}^n} with no fixed points.

Original entry on oeis.org

1, 0, 1, 56, 748521, 2671644472544, 4165949769769961828425, 4198063809561374304863859278045664, 3792196761630663647644729491214828673313675120817, 4066336002770373278819438293126282402268149361469069425278228336256
Offset: 0

Views

Author

Alois P. Heinz, Aug 27 2024

Keywords

Examples

			a(0) = 1: the empty permutation.
a(2) = 1: 2211.
a(3) = 56: 222333111, 223133112, 223133121, 223133211, 223313112, 223313121, 223313211, 223331112, 223331121, 223331211, 232133112, 232133121, 232133211, 232313112, 232313121, 232313211, 232331112, 232331121, 232331211, 233113122, 233113212, 233113221, 233131122, 233131212, 233131221, 233311122, 233311212, 233311221, 322133112, 322133121, 322133211, 322313112, 322313121, 322313211, 322331112, 322331121, 322331211, 323113122, 323113212, 323113221, 323131122, 323131212, 323131221, 323311122, 323311212, 323311221, 332113122, 332113212, 332113221, 332131122, 332131212, 332131221, 332311122, 332311212, 332311221, 333111222.
		

Crossrefs

Main diagonal of A372307.

Programs

  • Maple
    a:= n-> (-1)^n*int(exp(-x)*orthopoly[L](n, x)^n, x=0..infinity):
    seq(a(n), n=0..10);
  • Mathematica
    a[n_] := (-1)^n*Integrate[Exp[-x]*LaguerreL[n, x]^n, {x, 0, Infinity}];
    Table[a[n], {n, 0, 10}] (* Jean-François Alcover, Sep 02 2024, after Alois P. Heinz *)

Formula

a(n) mod 2 = 1 - (n mod 2) = A059841(n).
Showing 1-2 of 2 results.