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 1-4 of 4 results.

A027441 a(n) = (n^4 + n)/2 (Row sums of an n X n X n magic cube, when it exists).

Original entry on oeis.org

0, 1, 9, 42, 130, 315, 651, 1204, 2052, 3285, 5005, 7326, 10374, 14287, 19215, 25320, 32776, 41769, 52497, 65170, 80010, 97251, 117139, 139932, 165900, 195325, 228501, 265734, 307342, 353655, 405015, 461776, 524304, 592977, 668185, 750330, 839826, 937099
Offset: 0

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Author

Keywords

Comments

Starting with offset 1 = binomial transform of (1, 8, 25, 30, 12, 0, 0, 0, ...). - Gary W. Adamson, May 20 2009

Crossrefs

Subsequence of A057590.

Programs

Formula

O.g.f.: x*(1+4*x+7*x^2)/(1-x)^5. - R. J. Mathar, Feb 13 2008
a(n) = Sum_{k=n..n^2} k; for n>0: a(n) = A037270(n) - A000217(n-1). - Reinhard Zumkeller, Jul 06 2010
a(n) = 5*a(n-1) - 10*a(n-2) + 10*a(n-3) - 5*a(n-4) + a(n-5). - Wesley Ivan Hurt, Aug 13 2014
a(n) = A071232(n) / n^2, for n > 0. - Wesley Ivan Hurt, Aug 13 2014
a(n) = A002061(n)*A000217(n). - Anton Zakharov, Dec 16 2016
a(n) = (n+1)*(a(n-1)/(n-1) + n*(n-1)), a(0)=0, a(1)=1. - Vladimir Kruchinin, Oct 10 2018

Extensions

More terms from Wesley Ivan Hurt, Aug 13 2014

A088020 a(n) = (n^2)!.

Original entry on oeis.org

1, 1, 24, 362880, 20922789888000, 15511210043330985984000000, 371993326789901217467999448150835200000000, 608281864034267560872252163321295376887552831379210240000000000
Offset: 0

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Author

Hugo Pfoertner, Sep 18 2003

Keywords

Comments

a(n) is the number of ways in which is possible to fill an n X n square matrix with n^2 distinct elements. - Stefano Spezia, Sep 16 2018

Crossrefs

Cf. A000142 (n!), A000290 (n^2).
Cf. A039622, A179268. - Reinhard Zumkeller, Jul 06 2010

Programs

  • GAP
    List([0..10],n->Factorial(n^2)); # Muniru A Asiru, Sep 17 2018
  • Magma
    [Factorial(n^2): n in [0..10]]; // Vincenzo Librandi, May 31 2011
    
  • Maple
    seq(factorial(n^2),n=0..10); # Muniru A Asiru, Sep 17 2018
  • Mathematica
    Table[(n^2)!,{n,0,9}] (* Vladimir Joseph Stephan Orlovsky, May 19 2011 *)
  • PARI
    for(n=0,10,print1((n^2)!,",")) \\ Herman Jamke (hermanjamke(AT)fastmail.fm), Oct 22 2006
    

A362187 a(n) = (n^2 - n)!.

Original entry on oeis.org

1, 1, 2, 720, 479001600, 2432902008176640000, 265252859812191058636308480000000, 1405006117752879898543142606244511569936384000000000, 710998587804863451854045647463724949736497978881168458687447040000000000000
Offset: 0

Views

Author

Stefano Spezia, Apr 10 2023

Keywords

Comments

The next term has 104 digits.
For n > 0, a(n) is the number of n X n matrices using all the integers from 1 to n^2 and having the main diagonal given.

Crossrefs

Programs

  • Mathematica
    a[n_]:=(n^2-n)!; Array[a,9,0]

Formula

a(n) = (n^2 - n)*a(n-1) for n > 1.
a(n) = A000142(A002378(n-1)) for n > 0.

A369523 a(n) = n*(n^2 - 1)!.

Original entry on oeis.org

1, 12, 120960, 5230697472000, 3102242008666197196800000, 61998887798316869577999908025139200000000, 86897409147752508696036023331613625269650404482744320000000000, 15860866523235520512929173666895185100358189521818149024850236796901838028800000000000000
Offset: 1

Views

Author

Thomas Scheuerle, Jan 25 2024

Keywords

Comments

a(n) is the number of ways to fill an n X n square matrix with n^2 distinct elements such that a chosen element is in a designated row (or alternatively a column).

Crossrefs

Programs

  • Maple
    seq(n*factorial(n^2-1), n=1..8);
  • Mathematica
    Table[n*(n^2-1)!, {n, 1, 8}]
  • PARI
    a(n) = n*(n^2-1)!

Formula

a(n) = (n^2)!/n.
a(n) = Integral_{x>=0} x^(n - 1)*exp(-x^(1/n)) dx.
Showing 1-4 of 4 results.