Tag: combinatorics

50 Count sums of two squares 2015-11-26T00:38:01.640

48 Extending OEIS: Counting Diamond Tilings 2015-06-04T12:22:11.520

46 Determine if a coin system is Canonical 2016-10-13T20:27:19.410

42 Has My Pie Been Bisected? 2016-06-04T04:29:54.907

40 Lazy battleship placement 2014-03-04T04:51:30.907

40 Every word from babab to zyzyz 2017-01-12T11:52:46.923

39 Generate Pascal's triangle 2011-10-20T18:16:53.283

39 The Urinal Protocol 2015-03-18T14:56:06.547

36 Catalan Numbers 2015-12-09T17:39:41.920

34 Amount of permutations on an NxNxN Rubik's Cube 2019-04-17T07:19:36.810

33 Brute-force the switchboard 2019-07-19T17:47:09.083

32 Tic-tac-toe with only crosses 2016-01-06T18:15:11.410

31 Longest domino chain 2017-01-03T11:46:16.747

30 Which Friends characters were really the best friends? 2015-07-07T04:41:09.140

30 Motzkin Numbers 2015-12-17T08:05:05.523

30 Absolute Sums of Sidi Polynomial Coefficients 2016-12-26T03:00:05.007

29 Arranging Bubbles 2017-01-12T18:12:53.280

28 Vampire Compatibility 2015-03-19T18:58:25.683

28 Stuffing primes in a box 2016-03-07T10:17:38.023

28 Figure Out the Android Lock Pattern 2016-08-22T20:38:22.113

28 List all multiplicative partitions of n 2016-12-26T22:38:07.357

28 Find Diffy Games 2017-03-30T18:48:27.120

27 Shortest power set implementation 2012-11-21T08:48:27.880

27 Golf me some cash from the ATM 2015-01-06T16:22:11.683

27 Hook length product 2015-05-31T23:21:02.410

27 Sums of prime factors 2015-12-18T22:12:05.563

27 Compute the multinomial coefficient 2016-01-14T14:39:55.137

27 Number of Straight-Chain Alk*nes of given length 2016-12-13T22:58:51.363

27 Smallest region of the plane that contains all free n-ominoes 2018-06-26T18:02:26.730

27 Never trust a mastermind 2020-08-11T10:25:59.760

26 Enumerate rhyme schemes 2016-02-03T18:42:12.867

26 Case Permutation 2016-05-31T13:17:26.517

25 Android Lock Screen 2014-03-31T18:23:33.027

25 Deranged !Combinatorics: Compute the Subfactorial 2017-03-26T17:00:19.690

25 Reuse your code! 2017-04-02T15:53:41.200

25 Maximal discrepancy-2 sequence with minimal entropy 2017-05-28T18:20:19.907

25 Arbitrary Randomness 2018-11-20T14:45:28.413

24 The Coin Problem 2015-09-06T16:17:48.857

24 Find The Rank Of A Word 2018-01-18T17:11:27.830

24 Sign-Swapping Sums 2018-05-10T01:27:51.880

24 Triangular domino tiling of an almost regular hexagon 2019-11-18T23:28:51.097

24 The square root of the square root of the square root of the… 2020-10-19T22:50:48.957

23 Bernoulli Numbers 2015-11-30T20:51:09.963

23 Rearranging the sequence 2016-02-03T21:49:26.677

23 Partial factorisations of a positive integer 2016-07-29T06:05:22.490

23 Number of cycles of a permutation 2016-08-01T23:29:31.680

23 List all ordered partitions of n 2016-09-22T09:01:35.817

23 Determine How many Wheels There Are 2017-10-23T17:27:32.867

23 Extend the most recent "nice" OEIS sequence: stepping stone puzzle on a grid 2020-10-07T19:02:32.890

22 Code-Golf: Permutations 2012-03-06T05:11:13.233

22 Generate the shortest De Bruijn 2014-12-23T21:06:22.837

22 Can you cast the spell? 2015-05-06T13:14:43.150

22 Random ASCII Art of the Day #5: Diamond Tilings 2015-06-03T14:14:48.643

22 Print all colorings of a 3x3 grid 2015-06-08T17:55:27.710

22 Calculate a Pedigree 2015-06-12T21:02:31.840

22 ​L​o​o​p​ ​I​t​ 2018-01-11T12:37:16.153

22 Count the number of shortest paths to n 2019-08-26T07:17:21.800

22 Counts Of Orderings Containing At Most K Of The Kth Class 2020-01-27T21:21:24.927

22 Concentric rings on a snub square tiling 2020-02-04T21:25:49.980

22 Impress Donald Knuth by counting polyominoes on the hyperbolic plane 2020-02-25T21:31:12.000

21 Combinatorial products of unique primes 2014-09-21T20:01:40.183

21 Forming Polyominoes with a Chain of Rods 2014-12-04T22:38:49.200

21 The Combinatorics of Transistor 2015-10-27T15:23:40.950

21 Calculate the partitions of N 2016-06-30T23:10:22.433

21 A penny saved is a penny 2016-10-20T20:14:44.367

21 Partition a square grid into parts of equal area 2019-01-24T01:01:24.247

21 (RGS 2/5) How many strings can you count within these character classes? 2020-02-28T08:02:25.867

21 Verify a Superpermutation 2020-07-24T07:13:29.473

21 Cut a triangle into equal-sized parts! 2020-08-25T05:33:12.183

21 Sequences of distinct positive integers 2020-10-14T20:48:44.480

20 Build a pair of spies that will throw stones into a river 2014-06-12T23:26:10.767

20 Rafting Problem (Knapsack variant) 2017-02-12T03:15:49.990

20 Anaglot Polygrams 2017-05-09T18:56:29.373

20 Compress a maximal discrepancy-2 sequence 2017-05-23T22:56:18.540

20 Pick-flatten a list 2017-11-06T19:59:57.757

20 Hand patterns in a card game 2017-11-19T23:55:50.680

20 Socket - Plug compatibility 2018-07-15T16:54:21.273

20 Cycles on the torus 2019-03-09T02:19:44.460

20 Largest monetary amount impossible to make with two types of coin 2020-01-11T00:46:56.077

20 Super permutations 2020-01-25T11:42:19.147

20 Penney-Conway odds 2020-04-23T03:38:56.853

20 The Caged Circles 2021-01-08T07:37:44.143

19 The number of possible numeric outcomes of parenthesizations of 2^2^...^2 2013-05-09T15:16:05.430

19 Random Golf of the Day #3: Integer Partitions 2015-02-23T15:25:03.613

19 Necklace splitting problem 2017-02-10T21:26:10.670

19 Number of distinct non-empty subsequences of binary expansion 2017-10-15T14:09:36.603

19 Single swaps of an array 2018-01-01T22:12:46.740

19 Is it a shuffle? 2018-01-02T15:48:33.933

19 Partitioning the grid into triangles 2018-11-27T21:10:02.647

19 (RGS 5/5) Computing the set of all set partitions with fixed sizes 2020-03-11T08:06:34.123

19 What can you see on a hexagonal spiral? 2020-03-18T08:07:42.973

19 Exactly N in a line 2020-04-25T01:12:06.400

19 Tiling a staircase with staircases 2020-09-09T00:33:56.367

18 Draw a range of mountain ranges 2014-09-18T00:57:57.537

18 Finding the Deadlock 2015-05-23T19:39:45.770

18 Find the sets of sums 2015-12-09T20:47:15.503

18 Inverse permutation index 2016-10-10T18:29:26.190

18 Fewest disk writes to defrag multiple files 2016-11-22T02:09:14.967

18 How many shuffles 2018-01-01T22:00:11.057