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.

A039622 Number of n X n Young tableaux.

Original entry on oeis.org

1, 1, 2, 42, 24024, 701149020, 1671643033734960, 475073684264389879228560, 22081374992701950398847674830857600, 220381378415074546123953914908618547085974856000, 599868742615440724911356453304513631101279740967209774643120000
Offset: 0

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Author

Keywords

Comments

Number of arrangements of 1,2,...,n^2 in an n X n array such that each row and each column is increasing. The problem for a 5 X 5 array was recently posed and solved in the College Mathematics Journal. See the links.
This is the factor g_n that appears in a conjectured formula for 2n-th moment of the Riemann zeta function on the critical line. (See Conrey articles.) - Michael Somos, Apr 15 2003 [Comment revised by N. J. A. Sloane, Jun 21 2016]
Number of linear extensions of the n X n lattice. - Mitch Harris, Dec 27 2005

Examples

			Using the hook length formula, a(4) = (16)!/(7*6^2*5^3*4^4*3^3*2^2) = 24024.
		

References

  • M. du Sautoy, The Music of the Primes, Fourth Estate / HarperCollins, 2003; see p. 284.

Crossrefs

Main diagonal of A060854.
Also a(2)=A000108(2), a(3)=A005789(3), a(4)=A005790(4), a(5)=A005791(5).

Programs

  • Magma
    A039622:= func< n | n eq 0 select 1 else Factorial(n^2)*(&*[Factorial(j)/Factorial(n+j): j in [0..n-1]]) >;
    [A039622(n): n in [0..12]]; // G. C. Greubel, Apr 21 2021
    
  • Maple
    a:= n-> (n^2)! *mul(k!/(n+k)!, k=0..n-1):
    seq(a(n), n=0..12);  # Alois P. Heinz, Apr 10 2012
  • Mathematica
    a[n_]:= (n^2)!*Product[ k!/(n+k)!, {k, 0, n-1}]; Table[ a[n], {n, 0, 12}] (* Jean-François Alcover, Dec 06 2011, after Pari *)
  • PARI
    a(n)=(n^2)!*prod(k=0,n-1,k!/(n+k)!)
    
  • Sage
    def A039622(n): return factorial(n^2)*product( factorial(j)/factorial(n+j) for j in (0..n-1))
    [A039622(n) for n in (0..12)] # G. C. Greubel, Apr 21 2021

Formula

a(n) = (n^2)! / Product_{k=1..2n-1} k^(n - |n-k|).
a(n) = 0!*1!*...*(k-1)! *(k*n)! / ( n!*(n+1)!*...*(n+k-1)! ) for k=n.
a(n) = A088020(n)/A107254(n) = A088020(n)*A000984(n)/A079478(n). - Henry Bottomley, May 14 2005
a(n) = A153452(prime(n)^n). - Naohiro Nomoto, Jan 01 2009
a(n) ~ sqrt(Pi) * n^(n^2+11/12) * exp(n^2/2+1/12) / (A * 2^(2*n^2-7/12)), where A = 1.28242712910062263687534256886979... is the Glaisher-Kinkelin constant (see A074962). - Vaclav Kotesovec, Feb 10 2015
From Peter Luschny, May 20 2019: (Start)
a(n) = (G(1+n)*G(2+n)^(2-n)*(n^2)!*(G(3+n)/Gamma(2+n))^(n-1))/(G(1+2*n)*n!) where G(x) is the Barnes G function.
a(n) = A127223(n) / A107252(n). (End)
a(n) = (Gamma(n^2 +1)/Gamma(n+1))*(G(n+1)*G(n+2)/G(2*n+1)), where G(n) is the Barnes G-function. - G. C. Greubel, Apr 21 2021
a(n+2) = (n+2) * A060856(n+1) for n >= 0. - Tom Copeland, May 30 2022

A107252 a(n) = Product_{k=0..n-1} (n+k)!/(k+1)!.

Original entry on oeis.org

1, 1, 6, 1440, 36288000, 184354652160000, 309071606732292096000000, 254046582743105184577722777600000000, 142518177743863255019484504453155074867200000000000
Offset: 0

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Author

Henry Bottomley, May 14 2005

Keywords

Examples

			a(3) = 1!*2!*3!*4!*5!/(1!*2!*3!*1!*2!) = 34560/24 = 1440.
		

Crossrefs

Programs

  • Magma
    [1] cat [(&*[Factorial(n+k)/Factorial(k+1): k in [0..n-1]]): n in [1..10]]; // G. C. Greubel, May 21 2019
    
  • Mathematica
    Table[Product[(n+k)!/(k+1)!,{k,0,n-1}],{n,0,10}] (* Alexander Adamchuk, Jul 10 2006 *)
    a[n_] := (BarnesG[1 + 2 n] n! ((BarnesG[2 + n] Gamma[2 + n])/ BarnesG[3 + n])^(-1 + n))/BarnesG[2 + n]^2; Table[a[n], {n, 0, 10}] (* Peter Luschny, May 20 2019 *)
  • PARI
    {a(n) = prod(k=0,n-1, (n+k)!/(k+1)!)}; \\ G. C. Greubel, May 21 2019
    
  • Sage
    [product(factorial(n+k)/factorial(k+1) for k in (0..n-1)) for n in (0..10)] # G. C. Greubel, May 21 2019

Formula

a(n) = (n+1)!*(n+2)!*...*(2n-1)!/(1!*2!*...*(n-1)!).
a(n) = A000178(2n-1)/(A000178(n)*A000178(n-1)).
a(n) = A079478(n)/A001813(n).
a(n) = A079478(n-1)*A006963(n+1).
a(n) = A107251(n)/A000108(n).
a(n) = A107251(n-1)*A009445(n-1).
a(n) = A107254(n)/A000142(n).
a(n) = A009963(2n-1, n-1).
a(n) = A009963(2n-1, n).
a(n) = (G(1+2*n)*n!*((G(2+n)*Gamma(2+n))/G(3+n))^(n-1))/G(2+n)^2, where G(x) is the Barnes G function. - Peter Luschny, May 20 2019
a(n) ~ A * 2^(2*n^2 - 7/12) * n^(n^2 - n - 5/12) / (sqrt(Pi) * exp(3*n^2/2 - n + 1/12)), where A is the Glaisher-Kinkelin constant A074962. - Vaclav Kotesovec, May 21 2019

A136411 a(n) = Product_{k=1..n} (2*k-1)^(2*n-2*k+1).

Original entry on oeis.org

1, 3, 135, 212625, 21097715625, 207248662456171875, 291128066470548703880859375, 79746389028864195813528714933837890625, 5570294521107277357810167397301815834831695556640625
Offset: 1

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Author

Ctibor O. Zizka, Mar 31 2008

Keywords

Crossrefs

Programs

  • Magma
    [(&*[(2*k-1)^(2*n-2*k+1): k in [1..n]]): n in [1..10]]; // G. C. Greubel, Oct 14 2018
  • Mathematica
    Table[Product[(2*k - 1)^(2*n - 2*k + 1), {k, 1, n}], {n, 1, 10}] (* Stefan Steinerberger, May 18 2008 *)
    sf[n_] := BarnesG[n + 2]; a[n_] := sf[2 n - 1]/(2^(n (n - 1)) sf[n - 1]^2); Table[a[n], {n, 1, 10}]  (* Robert Coquereaux, Apr 02 2013 *)
  • PARI
    a(n) = prod(k=1, n, (2*k-1)^(2*n-2*k+1)) \\ Anders Hellström, Sep 16 2015
    

Formula

a(n) = A107254(n) / 2^(n*(n - 1)).
a(n) = sf(2*n-1) / (2^(n*(n-1)) * sf(n-1)^2), n >= 1, where sf(n) = BarnesG(n + 2) is the superfactorial defined in A000178. - Robert Coquereaux, Apr 02 2013
a(n) ~ A * 2^(n^2 + n - 1/12) * n^(n^2 + 1/12) / exp(3*n^2/2 + 1/12), where A = A074962 = 1.2824271291... is the Glaisher-Kinkelin constant. - Vaclav Kotesovec, Jul 10 2015

Extensions

More terms from Stefan Steinerberger, May 18 2008

A325053 a(n) = Product_{i=0..n, j=0..n} (i! + j! + 1).

Original entry on oeis.org

3, 81, 103680, 447180963840, 7014935716261432173527040, 1921470539412808834455592518302690305036517376000, 81601182941928855942156180258180656419177691149082352022004942698629910149621350400000
Offset: 0

Views

Author

Vaclav Kotesovec, Mar 26 2019

Keywords

Crossrefs

Programs

  • Mathematica
    Table[Product[i! + j! + 1, {i, 0, n}, {j, 0, n}], {n, 0, 7}]

Formula

a(n) = A306729(n) * Product_{i=0..n, j=0..n} (1 + 1/(i! + j!)).
a(n) ~ c * A324569 * 2^(n^2/2 + 2*n) * Pi^(n^2/2 + n) * n^(2*n^3/3 + 2*n^2 + 11*n/6 + 5/2) / exp(8*n^3/9 + 2*n^2 + n), where c = Product_{i>=0, j>=0} (1 + 1/(i! + j!)) = 71.32069635593350979104242285703294604508330622582076432053456223608...
Showing 1-4 of 4 results.