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 1-10 of 10 results.

A094050 Duplicate of A000479.

Original entry on oeis.org

1, 1, 2, 24, 1344, 1128960
Offset: 1

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Keywords

Crossrefs

Cf. A000479.

A002860 Number of Latin squares of order n; or labeled quasigroups.

Original entry on oeis.org

1, 2, 12, 576, 161280, 812851200, 61479419904000, 108776032459082956800, 5524751496156892842531225600, 9982437658213039871725064756920320000, 776966836171770144107444346734230682311065600000
Offset: 1

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Author

Keywords

Comments

Also the number of minimum vertex colorings in the n X n rook graph. - Eric W. Weisstein, Mar 02 2024

References

  • David Nacin, "Puzzles, Parity Maps, and Plenty of Solutions", Chapter 15, The Mathematics of Various Entertaining Subjects: Volume 3 (2019), Jennifer Beineke & Jason Rosenhouse, eds. Princeton University Press, Princeton and Oxford, p. 245.
  • Clifford A. Pickover, The Math Book, From Pythagoras to the 57th Dimension, 250 Milestones in the History of Mathematics, Sterling Publ., NY, 2009.
  • J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 210.
  • H. J. Ryser, Combinatorial Mathematics. Mathematical Association of America, Carus Mathematical Monograph 14, 1963, p. 53.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A098679 (Latin cubes).
A row of the array in A249026.

Programs

  • Mathematica
    Table[Length[ResourceFunction["FindProperColorings"][GraphProduct[CompleteGraph[n], CompleteGraph[n], "Cartesian"], n]], {n, 5}]

Formula

a(n) = n!*A000479(n) = n!*(n-1)!*A000315(n).

Extensions

One more term (from the McKay-Wanless article) from Richard Bean, Feb 17 2004

A000315 Number of reduced Latin squares of order n; also number of labeled loops (quasigroups with an identity element) with a fixed identity element.

Original entry on oeis.org

1, 1, 1, 4, 56, 9408, 16942080, 535281401856, 377597570964258816, 7580721483160132811489280, 5363937773277371298119673540771840
Offset: 1

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Comments

A reduced Latin square of order n is an n X n matrix where each row and column is a permutation of 1..n and the first row and column are 1..n in increasing order. - Michael Somos, Mar 12 2011
The Stones-Wanless (2010) paper shows among other things that a(n) is 0 mod n if n is composite and 1 mod n if n is prime.

References

  • L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 183.
  • J. Denes, A. D. Keedwell, editors, Latin Squares: new developments in the theory and applications, Elsevier, 1991, pp. 1, 388.
  • R. A. Fisher and F. Yates, Statistical Tables for Biological, Agricultural and Medical Research. 6th ed., Hafner, NY, 1963, p. 22.
  • C. R. Rao, S. K. Mitra and A. Matthai, editors, Formulae and Tables for Statistical Work. Statistical Publishing Society, Calcutta, India, 1966, p. 193.
  • J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 210.
  • H. J. Ryser, Combinatorial Mathematics. Mathematical Association of America, Carus Mathematical Monograph 14, 1963, pp. 37, 53.
  • N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
  • M. B. Wells, Elements of Combinatorial Computing. Pergamon, Oxford, 1971, p. 240.

Crossrefs

Formula

a(n) = A002860(n) / (n! * (n-1)!) = A000479(n) / (n-1)!.

Extensions

Added June 1995: the 10th term was probably first computed by Eric Rogoyski
a(11) (from the McKay-Wanless article) from Richard Bean, Feb 17 2004

A274171 Number of diagonal Latin squares of order n with the first row in order.

Original entry on oeis.org

1, 0, 0, 2, 8, 128, 171200, 7447587840, 5056994653507584
Offset: 1

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Author

Eduard I. Vatutin, Jul 07 2016

Keywords

Comments

A diagonal Latin square is a Latin square in which both the main diagonal and main antidiagonal contain each element. - Andrew Howroyd, Sep 29 2020

Examples

			The a(4) = 2 diagonal Latin squares are:
   0 1 2 3   0 1 2 3
   2 3 0 1   3 2 1 0
   3 2 1 0   1 0 3 2
   1 0 3 2   2 3 0 1
.
The a(5) = 8 diagonal Latin squares are:
   0 1 2 3 4   0 1 2 3 4   0 1 2 3 4   0 1 2 3 4
   1 3 4 2 0   1 4 3 0 2   2 3 4 0 1   2 4 1 0 3
   4 2 1 0 3   3 2 1 4 0   4 0 1 2 3   4 0 3 2 1
   2 0 3 4 1   4 3 0 2 1   1 2 3 4 0   3 2 4 1 0
   3 4 0 1 2   2 0 4 1 3   3 4 0 1 2   1 3 0 4 2
.
   0 1 2 3 4   0 1 2 3 4   0 1 2 3 4   0 1 2 3 4
   3 4 0 1 2   3 4 1 2 0   4 2 0 1 3   4 2 3 0 1
   1 2 3 4 0   4 2 3 0 1   1 4 3 2 0   3 4 1 2 0
   4 0 1 2 3   2 0 4 1 3   3 0 1 4 2   1 3 0 4 2
   2 3 4 0 1   1 3 0 4 2   2 3 4 0 1   2 0 4 1 3
		

Crossrefs

Formula

a(n) = A274806(n)/n!.

Extensions

a(9) added from Vatutin et al. (2016) by Max Alekseyev, Oct 05 2016
a(9) corrected by Eduard I. Vatutin, Oct 20 2016

A274806 Number of diagonal Latin squares of order n.

Original entry on oeis.org

1, 0, 0, 48, 960, 92160, 862848000, 300286741708800, 1835082219864832081920
Offset: 1

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Author

Eduard I. Vatutin, Jul 07 2016

Keywords

Comments

A diagonal Latin square is a Latin square in which both the main diagonal and main antidiagonal contain each element. - Andrew Howroyd, Oct 05 2020

Crossrefs

Formula

a(n) = A274171(n) * n!.

Extensions

a(9) from Vatutin et al. (2016) added by Max Alekseyev, Oct 05 2016
a(9) corrected by Eduard I. Vatutin, Oct 20 2016

A000528 Number of types of Latin squares of order n. Equivalently, number of nonisomorphic 1-factorizations of K_{n,n}.

Original entry on oeis.org

1, 1, 1, 2, 2, 17, 324, 842227, 57810418543, 104452188344901572, 6108088657705958932053657
Offset: 1

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Comments

Here "type" means an equivalence class of Latin squares under the operations of row permutation, column permutation, symbol permutation and transpose. In the 1-factorizations formulation, these operations are labeling of left side, labeling of right side, permuting the order in which the factors are listed and swapping the left and right sides, respectively. - Brendan McKay
There are 6108088657705958932053657 isomorphism classes of one-factorizations of K_{11,11}. - Petteri Kaski (petteri.kaski(AT)cs.helsinki.fi), Sep 18 2009

References

  • CRC Handbook of Combinatorial Designs, 1996, p. 660.
  • Denes and Keedwell, Latin Squares and Applications, Academic Press 1974.

Crossrefs

See A040082 for another version.

Extensions

More terms from Richard Bean, Feb 17 2004
a(11) from Petteri Kaski (petteri.kaski(AT)cs.helsinki.fi), Sep 18 2009

A114631 Number of even fixed diagonal Latin squares.

Original entry on oeis.org

1, 1, 0, 24, 384, 702720, 6231859200, 1364560466411520
Offset: 1

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Author

Eric W. Weisstein, Dec 18 2005

Keywords

Crossrefs

A114632 Number of odd fixed diagonal Latin squares.

Original entry on oeis.org

0, 0, 2, 0, 960, 426240, 5966438400, 1333257798942720
Offset: 1

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Author

Eric W. Weisstein, Dec 18 2005

Keywords

Crossrefs

A344664 a(n) is the number of preference profiles in the stable marriage problem with n men and n women where both the men's and the women's preferences form a Latin square when arranged in a matrix. In addition, it is possible to arrange all people into n man-woman couples such that they rank each other first.

Original entry on oeis.org

1, 2, 24, 13824, 216760320, 917676490752000, 749944260264355430400000, 293457967200879687743551498616832000, 84112872283641495670736269523436185936222748672000, 27460610008848610956892895086773773421767179663217968124264448000000
Offset: 1

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Author

Tanya Khovanova and MIT PRIMES STEP Senior group, Jun 01 2021

Keywords

Comments

Two people who rank each other first are called soulmates. Thus, the profiles in this sequence have n pairs of soulmates.
The profiles with n pairs of soulmates are counted by sequence A343698. The profiles such that the men's preferences form a Latin square are counted by A343696. The profiles such that both men's and women's preferences form a Latin square are counted by A343697. The profiles in this sequence are the intersection of profiles in A343698 and A343697.
Both the men- and the women-proposing Gale-Shapley algorithm on the preference profiles described by this sequence end in one round.

Examples

			For n = 3, there are A002860(3) = 12 Latin squares of order 3. Thus, there are A002860(3) = 12 ways to set up the men's preference profiles. After that, the women's preference profiles form a Latin square with a fixed first column, as the first column is uniquely defined to generate 3 pairs of soulmates. Thus, there are A002860(3)/3! = 12/6 = 2 ways to set up the women's preference profiles, making a(3) = 12 * 2 = 24 preference profiles.
		

Crossrefs

Formula

a(n) = A002860(n)^2 / n!.
a(n) = A000479(n) * A002860(n).

Extensions

Corrected by Tanya Khovanova, Aug 17 2021

A264603 Number of structurally distinct Latin squares of order n.

Original entry on oeis.org

1, 1, 1, 12, 192, 145164, 1524901344
Offset: 1

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Author

N. J. A. Sloane, Nov 23 2015

Keywords

Comments

"Structurally distinct" means that the squares cannot be made identical by means of rotation, reflection, and/or permutation of the symbols. For other notions of distinctness, see A000479 and A040082.

References

  • Hendrik Willem Barink, Email to N. J. A. Sloane, Nov 22 2015

Crossrefs

Extensions

a(7) from MSE link, added by Max Alekseyev, Sep 01 2017
Showing 1-10 of 10 results.