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.

Previous Showing 11-17 of 17 results.

A372307 Square array read by antidiagonals: T(n,k) is the number of derangements of a multiset comprising n repeats of a k-element set.

Original entry on oeis.org

1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 2, 1, 0, 1, 1, 9, 10, 1, 0, 1, 1, 44, 297, 56, 1, 0, 1, 1, 265, 13756, 13833, 346, 1, 0, 1, 1, 1854, 925705, 6699824, 748521, 2252, 1, 0, 1, 1, 14833, 85394646, 5691917785, 3993445276, 44127009, 15184, 1, 0, 1
Offset: 0

Views

Author

Jeremy Tan, Apr 26 2024

Keywords

Comments

A deck has k suits of n cards each. The deck is shuffled and dealt into k hands of n cards each. A match occurs for every card in the i-th hand of suit i. T(n,k) is the number of ways of achieving no matches. The probability of no matches is T(n,k)/((n*k)!/n!^k).
T(n,k) is the maximal number of totally mixed Nash equilibria in games of k players, each with n+1 pure options.

Examples

			Square array T(n,k) begins:
  1, 1, 1,      1,            1,                   1, ...
  1, 0, 1,      2,            9,                  44, ...
  1, 0, 1,     10,          297,               13756, ...
  1, 0, 1,     56,        13833,             6699824, ...
  1, 0, 1,    346,       748521,          3993445276, ...
  1, 0, 1,   2252,     44127009,       2671644472544, ...
  1, 0, 1,  15184,   2750141241,    1926172117389136, ...
  1, 0, 1, 104960, 178218782793, 1463447061709156064, ...
		

Crossrefs

Columns 0-4 give A000012, A000007, A000012, A000172, A371252.
Main diagonal gives A375778.

Programs

  • Maple
    A:= (n, k)-> (-1)^(n*k)*int(exp(-x)*orthopoly[L](n, x)^k, x=0..infinity):
    seq(seq(A(n, d-n), n=0..d), d=0..10);  # Alois P. Heinz, Aug 27 2024
  • Mathematica
    Table[Abs[Integrate[Exp[-x] LaguerreL[n, x]^(s-n), {x, 0, Infinity}]], {s, 0, 9}, {n, 0, s}] // Flatten
  • Python
    # See link.

Formula

T(n,k) = (-1)^(n*k) * Integral_{x=0..oo} exp(-x)*L_n(x)^k dx, where L_n(x) is the Laguerre polynomial of degree n (Even and Gillis).
T(n,k) ~ A089759(n,k)/exp(n).

A120666 Triangle read by rows: T(n, k) = (n*k)!/(n!)^k.

Original entry on oeis.org

1, 1, 6, 1, 20, 1680, 1, 70, 34650, 63063000, 1, 252, 756756, 11732745024, 623360743125120, 1, 924, 17153136, 2308743493056, 1370874167589326400, 2670177736637149247308800, 1, 3432, 399072960, 472518347558400, 3177459078523411968000, 85722533226982363751829504000, 7363615666157189603982585462030336000
Offset: 1

Views

Author

Roger L. Bagula, Aug 11 2006

Keywords

Comments

T(m,n) is the number of ways to distribute n*m different toys among m different kids so that each kid gets exactly n toys. For example, with n=3 and m=2, the 6 different toys, t1, t2, t3, t4, t5 and t6, can be distributed in exactly 20 ways among the 2 kids, k1 and k2, since there are C(6,3)=20 ways to choose the three toys for k1, with the other three toys going to k2. The proof for the general case is based on the identity C(n*m,n)*C(n*m-n,n)*...*C(n*m-n*(m-1),n) = (n*m)!/(n!)^m. - Dennis P. Walsh, Apr 12 2018

Examples

			Triangle begins:
  1;
  1,   6;
  1,  20,   1680;
  1,  70,  34650,    63063000;
  1, 252, 756756, 11732745024, 623360743125120;
		

Crossrefs

Programs

  • Magma
    [Factorial(n*k)/(Factorial(n))^k: k in [1..n], n in [1..10]]; // G. C. Greubel, Dec 26 2022
    
  • Maple
    T:= (m, n)-> (n*m)!/(m!)^n:
    seq(seq(T(m, n), n=1..m), m=1..7);  # Alois P. Heinz, Apr 12 2018
  • Mathematica
    Table[(n*k)!/(n!)^k, {n,10}, {k,n}]//Flatten
  • SageMath
    def A120666(n,k): return gamma(n*k+1)/(factorial(n))^k
    flatten([[A120666(n,k) for k in range(1,n+1)] for n in range(1,11)]) # G. C. Greubel, Dec 26 2022

Formula

T(n, k) = (k*n)!/(n!)^k.

Extensions

Edited by N. J. A. Sloane, Jun 17 2007
Offset corrected by Alois P. Heinz, Apr 12 2018
New name using formula by Joerg Arndt, Apr 15 2018

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.

A198801 Number of closed paths of length 19n whose steps are 19th roots of unity.

Original entry on oeis.org

1, 121645100408832000, 997586474354936812896742294502400000000, 66507379539349211518364492838558005847493108039680000000000000, 11256716378122801825351385824819232115042452248916289339300576523719750000000000000000
Offset: 0

Views

Author

Simon Plouffe, Oct 30 2011

Keywords

Comments

Equivalently, the number of paths of length 19n in Z^19 from {0}^19 to {n}^19. - Andrew Howroyd, Nov 01 2018

Crossrefs

Row n=19 of A187783, column k=19 of A089759.

Programs

Formula

a(n) = (19*n)!/(n!)^19. - Andrew Howroyd, Nov 01 2018

Extensions

Sequence redefined and a(2)-a(4) from Andrew Howroyd, Nov 01 2018

A198803 Number of closed paths of length 17n whose steps are 17th roots of unity.

Original entry on oeis.org

1, 355687428096000, 2252447502438386084347676160000000, 91637618063484032681381970173925718228992000000000000, 8528384964488882787308232082310780143738202829970606470279000000000000000
Offset: 0

Views

Author

Simon Plouffe, Oct 30 2011

Keywords

Comments

Equivalently, the number of paths of length 17n in Z^17 from {0}^17 to {n}^17. - Andrew Howroyd, Nov 01 2018

Crossrefs

Row n=17 of A187783, column k=17 of A089759.

Programs

Formula

a(n) = (17*n)!/(n!)^17. - Andrew Howroyd, Nov 01 2018

Extensions

Sequence redefined and a(2)-a(4) from Andrew Howroyd, Nov 01 2018

A198809 Number of closed paths of length 11n whose steps are 11th roots of unity.

Original entry on oeis.org

1, 39916800, 548828480360160000, 23934366266775567482880000000, 1746930746117010628955362040959500000000, 170878335353097656943918169452451079403744627916800, 20193738534370392855946567010492898163504440783192016158720000
Offset: 0

Views

Author

Simon Plouffe, Oct 30 2011

Keywords

Comments

Equivalently, the number of paths of length 11n in Z^11 from {0}^11 to {n}^11. - Andrew Howroyd, Nov 01 2018

Crossrefs

Row n=11 of A187783, column k=11 of A089759.

Programs

Formula

a(n) = (11*n)!/(n!)^11. - Andrew Howroyd, Nov 01 2018

Extensions

Sequence redefined and a(2)-a(6) from Andrew Howroyd, Nov 01 2018

A198807 Number of closed paths of length 13n whose steps are 13th roots of unity.

Original entry on oeis.org

1, 6227020800, 49229914688306352000000, 1561776277448122046153927884800000000, 92024242230271040357108320801872044844750000000000, 7708574168669332219803079339976372645861971547841327593737420800
Offset: 0

Views

Author

Simon Plouffe, Oct 30 2011

Keywords

Comments

Equivalently, the number of paths of length 13n in Z^13 from {0}^13 to {n}^13. - Andrew Howroyd, Nov 01 2018

Crossrefs

Row n=13 of A187783, column k=13 of A089759.

Programs

Formula

a(n) = (13*n)!/(n!)^13. - Andrew Howroyd, Nov 01 2018

Extensions

Sequence redefined and a(2)-a(5) from Andrew Howroyd, Nov 01 2018
Previous Showing 11-17 of 17 results.