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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A067228 Number of rectangular standard Young tableaux with n cells.

Original entry on oeis.org

1, 2, 2, 4, 2, 12, 2, 30, 44, 86, 2, 1190, 2, 860, 12014, 26886, 2, 184758, 2, 3359202, 2771342, 117574, 2, 327618902, 701149022, 1485802, 828630662, 27350160662, 2, 808310933492, 2, 2979826568702, 291724349282, 259289582, 557214344578322, 2031957220875002, 2
Offset: 1

Views

Author

Naohiro Nomoto, Feb 20 2002

Keywords

Comments

Number of ways to arrange the numbers 1, 2, .., n=i*j into an i*j rectangle so that each row and each column is increasing.
a(p) = 2 for prime p. - Alois P. Heinz, Jul 25 2012

Crossrefs

Column k=0 of A238707.

Programs

  • Maple
    with(numtheory):
    a:= n-> n! * add(mul(k!/(i+k)!, k=0..(n/i)-1), i=divisors(n)):
    seq(a(n), n=1..40);  # Alois P. Heinz, Jul 25 2012
  • Mathematica
    a[n_] := n! * Sum[Product[k!/(i+k)!, {k, 0, n/i-1}], {i, Divisors[n]}]; Table[a[n], {n, 1, 40}] (* Jean-François Alcover, Jul 02 2015, after Alois P. Heinz *)

Formula

a(n) = n! * Sum_{i|n} Product_{k=0..n/i-1} k!/(i+k)!. - Alois P. Heinz, Jul 25 2012

Extensions

Better name from Joerg Arndt, Feb 24 2014

A321977 8-dimensional Catalan numbers.

Original entry on oeis.org

1, 1, 1430, 23371634, 1489877926680, 231471904322784840, 67867669180627125604080, 32103104214166146088869942000, 22081374992701950398847674830857600, 20535535214275361308250745082811167425600, 24486819823897171791550434989846505231774984000
Offset: 0

Views

Author

Seiichi Manyama, Nov 23 2018

Keywords

Comments

Number of n X 8 Young tableaux.

Crossrefs

Programs

  • GAP
    List([0..15],n->125411328000*Factorial(8*n)/Product([0..7],k->Factorial(n+k))); # Muniru A Asiru, Nov 25 2018
  • Magma
    [125411328000*Factorial(8*n)/(Factorial(n)*Factorial(n + 1)*Factorial(n + 2)*Factorial(n + 3)*Factorial(n + 4)*Factorial(n + 5)*Factorial(n + 6)*Factorial(n + 7)): n in [0..15]]; // Vincenzo Librandi, Nov 24 2018
    
  • Mathematica
    Table[125411328000 (8 n)! / (n! (n+1)! (n+2)! (n+3)! (n+4)! (n+5)! (n+6)! (n + 7)!), {n, 0, 15}] (* Vincenzo Librandi, Nov 24 2018 *)

Formula

a(n) = 0!*1!*...*7! * (8*n)! / ( n!*(n+1)!*...*(n+7)! ).
a(n) ~ 1913625 * 2^(24*n + 14) / (Pi^(7/2) * n^(63/2)). - Vaclav Kotesovec, Nov 23 2018

A067231 Number of Young tableaux with n=i*j cells and type i*j matrices with i>=j.

Original entry on oeis.org

1, 1, 1, 3, 1, 6, 1, 15, 43, 43, 1, 595, 1, 430, 6007, 25455, 1, 92379, 1, 1679601, 1385671, 58787, 1, 163809451, 701149021, 742901, 414315331, 13675080331, 1, 404155466746, 1, 1489913284351, 145862174641, 129644791, 278607172289161, 1851800127304981, 1
Offset: 1

Views

Author

Naohiro Nomoto, Feb 20 2002

Keywords

Comments

a(p) = 1 for prime p. - Alois P. Heinz, Jul 25 2012

Crossrefs

Programs

  • Maple
    with(numtheory):
    a:= n-> n!*add(mul(k!/(i+k)!, k=0..n/i-1),
            i=select(d-> is(d>=sqrt(n)), divisors(n))):
    seq(a(n), n=1..40);  # Alois P. Heinz, Jul 25 2012
  • Mathematica
    a[n_] := n!*Sum[Product[k!/(i+k)!, {k, 0, n/i-1}], {i, Select[Divisors[n], # >= Sqrt[n]&]}]; Table[a[n], {n, 1, 40}] (* Jean-François Alcover, Mar 23 2017, translated from Maple *)

Formula

a(n) = number of ways to arrange the numbers 1, 2, .., n=i*j in i*j matrices so that each row and each column is increasing. Here i and j satisfy i >= j.
a(n) = n! * Sum_{i|n, i>=sqrt(n)} Product_{k=0..n/i-1} k!/(i+k)!. - Alois P. Heinz, Jul 25 2012

A211400 Rectangular array, read by upward diagonals: T(n,m) is the number of Young tableaux that can be realized as the ranks of the outer sums a_i + b_j where a = (a_1, ... a_n) and b = (b_1, ... b_m) are real monotone vectors in general position (all sums different).

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 1, 5, 5, 1, 1, 14, 36, 14, 1, 1, 42, 295, 295, 42, 1, 1, 132, 2583, 6660, 2583, 132, 1, 1, 429, 23580
Offset: 1

Views

Author

Colin Mallows, Feb 08 2013

Keywords

Comments

Alternatively, that can be realized as the ranks of the outer products a_i b_j where a = (a_1, ... a_n) and b = (b_1, ... b_m) are real positive monotone vectors.
The entries at T(2,n) and T(m,2) are Catalan numbers (A000108).
The original version of this sequence was
1 1 1 1 1 1 1 ...
1 2 5 14 42 132 428 ...
1 5 24 77 ...
1 14 77 ...
1 42 ...
...
but some of the later entries seem to be incorrect. - Robert J. Vanderbei, Jan 09 2015

Examples

			The vectors a = (0,2) and b = (0,4,5) give the outer sums
0  4  5  which have ranks  1  3  4
2  6  7                    2  5  6
which is one of the five 2 X 3 Young tableaux.
One of the 18 3 X 3 tableaux that cannot be realized as a set of outer sums
is  1  2  6
    3  5  7
    4  8  9.
The array begins
1      1      1      1      1      1      1      1      1 ...
1      2      5     14     42    132    429   1430   4862 ... (A000108)
1      5     36    295   2583  23580 221680    ... (A255489)
1     14    295   6660    ...
1     42   2583    ...
1    132  23580    ...
1    429 221680    ...
1   1430   ...
1   4862   ...
...
		

Crossrefs

Extensions

Corrected and extended by Robert J. Vanderbei, Jan 09 2015

A215287 Number of permutations of 0..floor((n*3-1)/2) on even squares of an n X 3 array such that each row and column of even squares is increasing.

Original entry on oeis.org

1, 3, 10, 30, 140, 420, 2310, 6930, 42042, 126126, 816816, 2450448, 16628040, 49884120, 350574510, 1051723530, 7595781050, 22787343150, 168212023980, 504636071940, 3792416540640, 11377249621920, 86787993910800, 260363981732400, 2011383287449200
Offset: 1

Views

Author

R. H. Hardin, Aug 07 2012

Keywords

Comments

Also Schröder paths of length n having floor(n/2) peaks. - Peter Luschny, Sep 30 2018

Examples

			Some solutions for n=5:
  0 x 4   0 x 5   1 x 3   0 x 1   0 x 3   1 x 4   0 x 2
  x 3 x   x 1 x   x 0 x   x 4 x   x 2 x   x 0 x   x 1 x
  1 x 5   2 x 6   2 x 5   2 x 3   1 x 6   2 x 5   3 x 5
  x 7 x   x 3 x   x 6 x   x 6 x   x 5 x   x 6 x   x 6 x
  2 x 6   4 x 7   4 x 7   5 x 7   4 x 7   3 x 7   4 x 7
		

Crossrefs

Column 3 of A215292.

Programs

  • Magma
    [(n-(n div 2)+1)*Factorial(2*n-(n div 2)) / (Factorial(n-(n div 2) +1)^2*Factorial((n div 2))): n in [1..30]]; // Vincenzo Librandi, Oct 01 2018
  • Maple
    T := (n, k) -> (n-k+1)*(2*n-k)!/((n-k+1)!^2*k!):
    a := n -> T(n, floor(n/2)): seq(a(n), n = 1..23); # Peter Luschny, Sep 30 2018
  • Mathematica
    Table[(n - Floor[n/2] + 1) (2 n - Floor[n/2])! / ((n -Floor[n/2] + 1)!^2 Floor[n/2]!), {n, 1, 30}] (* Vincenzo Librandi, Oct 01 2018 *)

Formula

f3 = floor((n+1)/2); f4 = floor(n/2);
a(n) = A060854(2,f3)*A060854(1,f4)*binomial(2*f3+1*f4,2*f3).
a(n) = (n - f + 1)*(2*n - f)! / ((n - f + 1)!^2 * f!) where f = floor(n/2). - Peter Luschny, Sep 30 2018

A215290 Number of permutations of 0..floor((n*6-1)/2) on even squares of an nX6 array such that each row and column of even squares is increasing.

Original entry on oeis.org

1, 20, 420, 23100, 1051050, 85765680, 5703417720, 577185873264, 48236247979920, 5595404765670720, 545152292883918720, 69506917342699636800, 7562187114225380722800, 1033498905610802032116000
Offset: 1

Views

Author

R. H. Hardin Aug 07 2012

Keywords

Comments

Column 6 of A215292

Examples

			Some solutions for n=4
..0..x..2..x..6..x....1..x..6..x..7..x....1..x..2..x..7..x....0..x..2..x..6..x
..x..1..x..3..x..5....x..0..x..2..x..4....x..0..x..4..x.10....x..3..x..5..x..7
..4..x..9..x.10..x....9..x.10..x.11..x....3..x..6..x..8..x....1..x..9..x.11..x
..x..7..x..8..x.11....x..3..x..5..x..8....x..5..x..9..x.11....x..4..x..8..x.10
		

Formula

f3=floor((n+1)/2)
f4=floor(n/2)
a(n) = A060854(3,f3)*A060854(3,f4)*binomial(3*f3+3*f4,3*f3)

A321716 Triangle read by rows: T(n,k) is the number of n X k Young tableaux, where 0 <= k <= n.

Original entry on oeis.org

1, 1, 1, 1, 1, 2, 1, 1, 5, 42, 1, 1, 14, 462, 24024, 1, 1, 42, 6006, 1662804, 701149020, 1, 1, 132, 87516, 140229804, 396499770810, 1671643033734960, 1, 1, 429, 1385670, 13672405890, 278607172289160, 9490348077234178440, 475073684264389879228560
Offset: 0

Views

Author

Seiichi Manyama, Nov 17 2018

Keywords

Examples

			T(4,3) = 12! / ((6*5*4)*(5*4*3)*(4*3*2)*(3*2*1)) = 462.
Triangle begins:
  1;
  1, 1;
  1, 1,   2;
  1, 1,   5,    42;
  1, 1,  14,   462,     24024;
  1, 1,  42,  6006,   1662804,    701149020;
  1, 1, 132, 87516, 140229804, 396499770810, 1671643033734960;
		

Crossrefs

Programs

  • Magma
    A321716:= func< n,k | n eq 0 select 1 else Factorial(n*k)/(&*[ Round(Gamma(j+k)/Gamma(j)): j in [1..n]]) >;
    [A321716(n,k): k in [0..n], n in [0..12]]; // G. C. Greubel, May 04 2021
    
  • Mathematica
    T[n_, k_]:= (n*k)!/Product[Product[i+j-1, {j,1,k}], {i,1,n}]; Table[T[n, k], {n, 0, 7}, {k, 0, n}] // Flatten (* Amiram Eldar, Nov 17 2018 *)
    T[n_, k_]:= (n*k)!*BarnesG[n+1]*BarnesG[k+1]/BarnesG[n+k+1];
    Table[T[n, k], {n, 0, 5}, {k, 0, n}] //Flatten (* G. C. Greubel, May 04 2021 *)
  • Sage
    def A321716(n,k): return factorial(n*k)/product( gamma(j+k)/gamma(j) for j in (1..n) )
    flatten([[A321716(n,k) for k in (0..n)] for n in (0..12)]) # G. C. Greubel, May 04 2021

Formula

T(n, k) = (n*k)! / (Product_{i=1..n} Product_{j=1..k} (i+j-1)).
T(n, k) = A060854(n,k) for n,k > 0.
T(n, n) = A039622(n).
T(n, k) = (n*k)!*BarnesG(n+1)*BarnesG(k+1)/BarnesG(n+k+1), where BarnesG(n) = A000178. - G. C. Greubel, May 04 2021

A321978 9-dimensional Catalan numbers.

Original entry on oeis.org

1, 1, 4862, 414315330, 177295473274920, 219738059326729823880, 583692803893929928888544400, 2760171874087743799855959353857200, 20535535214275361308250745082811167425600, 220381378415074546123953914908618547085974856000
Offset: 0

Views

Author

Seiichi Manyama, Nov 23 2018

Keywords

Comments

Number of n X 9 Young tableaux.

Crossrefs

Programs

  • GAP
    List([0..10],n->5056584744960000*Factorial(9*n)/Product([0..8],k->Factorial(n+k))); # Muniru A Asiru, Nov 25 2018
  • Magma
    [5056584744960000*Factorial(9*n)/(Factorial(n)*Factorial(n + 1)*Factorial(n + 2)*Factorial(n + 3)*Factorial(n + 4)*Factorial(n + 5)*Factorial(n + 6)*Factorial(n + 7)*Factorial(n + 8)): n in [0..15]]; // Vincenzo Librandi, Nov 24 2018
    
  • Mathematica
    Table[5056584744960000 (9 n)! / (n! (n + 1)! (n + 2)! (n + 3)! (n + 4)! (n + 5)! (n + 6)! (n + 7)! (n + 8)!), {n, 0, 15}] (* Vincenzo Librandi, Nov 24 2018 *)

Formula

a(n) = 0!*1!*...*8! * (9*n)! / ( n!*(n+1)!*...*(n+8)! ).
a(n) ~ 16056320000 * 3^(18*n + 10) / (Pi^4 * n^40). - Vaclav Kotesovec, Nov 23 2018

A062528 Number of ways to fill an n X n matrix with numbers 1, 2, ..., n*n such that each row and each column is decreasing or increasing.

Original entry on oeis.org

1, 24, 736, 486200, 15717093608, 41301356272912040, 12775545227876350768099688, 645382645785863222088428068265093848, 6899505383250315051751361998008633233501722290328
Offset: 1

Views

Author

Floor van Lamoen, Jul 10 2001

Keywords

Comments

From Jon E. Schoenfield, Aug 16 2009: (Start)
Number the rows of the matrix as 1..n from bottom to top, and the columns as 1..n from left to right. For i=1..n, let r(i)=1 if the i-th row increases toward the right, -1 if it decreases; let R be the number of runs of consecutive rows having the same r value, and let LR(k) be the length of the k-th run, for k=1..R. Similarly, for i=1..n, let c(i)=1 if the i-th column increases toward the top, -1 if it decreases; let C be the number of runs of consecutive columns having the same c value, and let LC(k) be the length of the k-th run, for k=1..C.
For each of the 4 possible combinations of the vectors r and c in which R=C=1, the number of solutions is A039622(n). In any combination where R=1 and C > 1, the matrix can be partitioned into C rectangular sections (the k-th one being LC(k) columns wide and n rows high); the numbers 1 through LC(1)*n must be placed in the first section, the next LC(2)*n numbers in the second section, etc., so the total number of solutions is Product_{k=1..C} T(LC(k),n), where T(m,n) is as defined at A060854; similarly, if C=1 and R > 1, the number of solutions is Product_{k=1..R} T(LR(k),n).
In any combination where R=2, C=2, and r(1)=c(1), the matrix can be partitioned into 4 rectangular sections, with the lower left and lower right sections covering rows 1..LR(1), the upper left and upper right covering the remaining rows, the lower and upper left covering columns 1..LC(1), and the lower and upper right covering the remaining columns. Then, if r(1)=c(1)=1, the numbers 1 through LR(1)*LC(1) + LR(2)*LC(2) must be apportioned between the lower left and upper right sections; if r(1)=c(1)=-1, they must be apportioned between the other two sections. Either way, the number of solutions for such a combination of the vectors r and c is binomial(LR(1)*LC(1) + LR(2)*LC(2), LR(1)*LC(1)) * binomial(LR(1)*LC(2) + LR(2)*LC(1), LR(1)*LC(2)) * T(LR(1), LC(1)) * T(LR(1), LC(2)) * T(LR(2), LC(1)) * T(LR(2), LC(2)).
No solutions exist where R=C=2 and r(1) != c(1), nor are there any solutions where R=2 and C > 2, R > 2 and C=2, or R > 2 and C > 2. (End)

Examples

			a(2) = 4! = 24 because every arrangement of the four elements of a 2 X 2 matrix satisfies the conditions.
		

Crossrefs

Cf. A039622.

Extensions

a(3) changed from 5320 to 736 by R. H. Hardin, Feb 17 2002
More terms from Jon E. Schoenfield, Aug 15 2009

A177847 Array T(n,m)= (n*m)!*Beta(n, m) read by antidiagonals.

Original entry on oeis.org

1, 1, 1, 2, 4, 2, 6, 60, 60, 6, 24, 2016, 12096, 2016, 24, 120, 120960, 7983360, 7983360, 120960, 120, 720, 11404800, 12454041600, 149448499200, 12454041600, 11404800, 720, 5040, 1556755200, 38109367296000, 8688935743488000, 8688935743488000
Offset: 1

Views

Author

Roger L. Bagula, May 14 2010

Keywords

Comments

Beta(x,y) = Gamma(x)*Gamma(y)/Gamma(x+y).

Examples

			The array starts in row n=1 as:
1,       1,           2,                6,                      24, ...
1,       4,          60,             2016,                  120960, ...
2,      60,       12096,          7983360,             12454041600, ...
6,    2016,     7983360,     149448499200,        8688935743488000, ...
24, 120960, 12454041600, 8688935743488000, 24620968322747596800000, ...
		

Crossrefs

Cf. A060854.

Programs

  • Maple
    A177847 := proc(n,m) (n*m)!*Beta(n,m) ; end proc:
    seq (seq (A177847(n, 1+d-n), n=1..d), d=1..10);
  • Mathematica
    t[n_, m_] = (n*m)!*Beta[n, m];
    a = Table[Table[t[n, m], {m, 1, 10}], {n, 1, 10}];
    Table[Table[a[[m, n - m + 1]], {m, 1, n}], {n, 1, 10}];
    Flatten[%]

Formula

T(n,m) = Gamma(n*m+1)*Gamma(n)*Gamma(m)/Gamma(n+m).
T(1,m) = A000142(m-1).
T(n,m) = T(m,n).
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