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.

Showing 1-2 of 2 results.

A047058 a(n) = 6^n * n!.

Original entry on oeis.org

1, 6, 72, 1296, 31104, 933120, 33592320, 1410877440, 67722117120, 3656994324480, 219419659468800, 14481697524940800, 1042682221795737600, 81329213300067532800, 6831653917205672755200, 614848852548510547968000
Offset: 0

Views

Author

Joe Keane (jgk(AT)jgk.org)

Keywords

Comments

For n >= 1, a(n) is the order of the wreath product of the symmetric group S_n and the Abelian group (C_6)^n. - Ahmed Fares (ahmedfares(AT)my-deja.com), May 07 2001
a(n) is the number of ways 3 members of each of n different teams can be arranged in a row so that members of the same team are together. - Geoffrey Critzer, Mar 30 2009
From Jianing Song, Mar 29 2021: (Start)
Number of n X n monomial matrices with entries 0, +/-1, +/-w, +/-w^2, where w = (-1 + sqrt(3)*i)/2 is a primitive 3rd root of unity.
a(n) is the order of the group U_n(Z[w]) = {A in M_n(Z[w]): A*A^H = I_n}, the group of n X n unitary matrices over the Eisenstein integers. Here A^H is the conjugate transpose of A. (End)

Crossrefs

Programs

Formula

a(n) = A051151(n+1, 0).
E.g.f.: 1/(1 - 6*x).
G.f.: 1/(1 -6*x/(1 - 6*x/(1 - 12*x/(1 - 12*x/(1 - 18*x/(1 - 18*x/(1 - 24*x/(1 - 24*x/(1 - 30*x/(1 - 30*x/(1 -... (continued fraction). - Philippe Deléham, Jan 08 2012
From Amiram Eldar, Jun 25 2020: (Start)
Sum_{n>=0} 1/a(n) = e^(1/6) (A092515).
Sum_{n>=0} (-1)^n/a(n) = e^(-1/6) (A092727). (End)

Extensions

Name changed by Arkadiusz Wesolowski, Oct 04 2011

A092727 Decimal expansion of e^(-1/6).

Original entry on oeis.org

8, 4, 6, 4, 8, 1, 7, 2, 4, 8, 9, 0, 6, 1, 4, 0, 7, 4, 0, 4, 4, 9, 1, 7, 3, 9, 9, 7, 9, 8, 7, 5, 4, 5, 7, 6, 8, 8, 8, 2, 9, 1, 6, 2, 4, 4, 2, 7, 0, 5, 1, 8, 3, 9, 3, 2, 2, 6, 5, 0, 9, 1, 4, 9, 8, 0, 1, 4, 1, 4, 7, 8, 7, 0, 5, 4, 6, 1, 4, 7, 4, 7, 4, 8, 2, 1, 6, 4, 7, 0, 3, 4, 2, 0, 1, 1, 5, 7, 5, 9, 3, 2, 5, 3, 1
Offset: 0

Views

Author

Mohammad K. Azarian, Apr 22 2004

Keywords

Examples

			0.84648172489061407404491739979875457688829162442705...
		

Crossrefs

Cf. A001113, A019774, A068985, A092515 (reciprocal).

Programs

  • Mathematica
    RealDigits[E^-(1/6),10,120][[1]] (* Harvey P. Dale, Jun 18 2012 *)

Formula

Equals lim_{x->0} (sin(x)/x)^(1/x^2). - Amiram Eldar, Jul 04 2022
Showing 1-2 of 2 results.